From 25b2d255aa925c445cb38a4c260ff7e5400fc65c Mon Sep 17 00:00:00 2001
From: Marc Durdin <marc@durdin.net>
Date: Thu, 1 Sep 2022 16:56:50 +1000
Subject: [PATCH 1/2] feat(developer): use json schema to verify source file

As we do not appear to have access to a good DTD validation library in
Node.js, we will instead convert the DTD to a JSON schema file and use
that for validation.

I have not verified every aspect of the JSON schema at this point, but
will incrementally do so as I implement further aspects of the compiler.

This updates all the testing to use the schema. As the schema validation
is slow, I have increased the 'normal' time for tests.
---
 developer/src/kmldmlc/build.sh                |   2 +
 developer/src/kmldmlc/package.json            |   7 +-
 .../kmldmlc/src/keyman/compiler/callbacks.ts  |   1 +
 .../src/kmldmlc/src/keyman/compiler/errors.ts |   4 +
 .../ldml-keyboard/ldml-keyboard-xml-reader.ts |  24 +-
 developer/src/kmldmlc/src/kmldmlc.ts          |   3 +
 .../fixtures/invalid-structure-per-dtd.xml    |   8 +
 developer/src/kmldmlc/test/helpers/index.ts   |   5 +
 .../test-ldml-keyboard-xml-reader.ts          |  19 +
 .../src/kmldmlc/test/test-compiler-e2e.ts     |   2 +
 developer/src/kmldmlc/test/test-loca.ts       |   2 +
 developer/src/kmldmlc/test/test-meta.ts       |   2 +
 package-lock.json                             |  63 +-
 .../standards-data/ldml-keyboards/readme.md   |   9 +
 .../techpreview/ldml-keyboard.schema.json     | 677 ++++++++++++++++++
 .../techpreview/ldmlKeyboard.xsd              | 304 ++++++++
 16 files changed, 1119 insertions(+), 13 deletions(-)
 create mode 100644 developer/src/kmldmlc/test/fixtures/invalid-structure-per-dtd.xml
 create mode 100644 developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
 create mode 100644 resources/standards-data/ldml-keyboards/techpreview/ldml-keyboard.schema.json
 create mode 100644 resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.xsd

diff --git a/developer/src/kmldmlc/build.sh b/developer/src/kmldmlc/build.sh
index 0008bf3a3d..d2191e1139 100755
--- a/developer/src/kmldmlc/build.sh
+++ b/developer/src/kmldmlc/build.sh
@@ -46,6 +46,8 @@ fi
 
 if builder_has_action build; then
   npm run build
+  # We need the schema file at runtime and bundled
+  cp "$KEYMAN_ROOT/resources/standards-data/ldml-keyboards/techpreview/ldml-keyboard.schema.json" "$THIS_SCRIPT_PATH/build/src/"
   builder_report success build
 fi
 
diff --git a/developer/src/kmldmlc/package.json b/developer/src/kmldmlc/package.json
index e6b0b87cdb..3b66eb82d3 100644
--- a/developer/src/kmldmlc/package.json
+++ b/developer/src/kmldmlc/package.json
@@ -9,7 +9,7 @@
   ],
   "scripts": {
     "build": "tsc -b",
-    "test": "cd test && tsc -b && cd .. && mocha ",
+    "test": "cd test && tsc -b && cd .. && mocha",
     "prepublishOnly": "npm run build"
   },
   "author": "Marc Durdin <marc@keyman.com> (https://github.com/mcdurdin)",
@@ -19,6 +19,7 @@
     "kmldmlc": "build/src/kmldmlc.js"
   },
   "dependencies": {
+    "ajv": "^8.11.0",
     "commander": "^3.0.0",
     "crc-32": "^1.2.2",
     "restructure": "^3.0.0",
@@ -37,7 +38,9 @@
     "ts-node": "^9.1.1"
   },
   "mocha": {
-    "spec": "build/test/test-*.js"
+    "spec": "build/test/**/test-*.js",
+    "require": ["source-map-support/register"]
+
   },
   "repository": {
     "type": "git",
diff --git a/developer/src/kmldmlc/src/keyman/compiler/callbacks.ts b/developer/src/kmldmlc/src/keyman/compiler/callbacks.ts
index 2cccb540df..8d32f5e8c4 100644
--- a/developer/src/kmldmlc/src/keyman/compiler/callbacks.ts
+++ b/developer/src/kmldmlc/src/keyman/compiler/callbacks.ts
@@ -5,5 +5,6 @@ export interface CompilerEvent {
 
 export default interface CompilerCallbacks {
   loadFile(baseFilename: string, filename: string): Buffer;
+  loadLdmlKeyboardSchema(): Buffer;
   reportMessage(event: CompilerEvent): void;
 };
diff --git a/developer/src/kmldmlc/src/keyman/compiler/errors.ts b/developer/src/kmldmlc/src/keyman/compiler/errors.ts
index 6d403421f6..79dbb03a65 100644
--- a/developer/src/kmldmlc/src/keyman/compiler/errors.ts
+++ b/developer/src/kmldmlc/src/keyman/compiler/errors.ts
@@ -37,6 +37,10 @@ export class CompilerErrors {
     m(this.HINT_OneOrMoreRepeatedLocales, `After minimization, one or more locales is repeated and has been removed`);
   static HINT_OneOrMoreRepeatedLocales = SevHint | 0x0006;
 
+  static InvalidFile = (errorText: string) =>
+    m(this.ERROR_InvalidFile, `The source file has an invalid structure: ${errorText}`);
+  static ERROR_InvalidFile = SevError | 0x0007;
+
   static severityName(code: number): string {
     let severity = code & CompilerErrorSeverity.Severity_Mask;
     switch(severity) {
diff --git a/developer/src/kmldmlc/src/keyman/ldml-keyboard/ldml-keyboard-xml-reader.ts b/developer/src/kmldmlc/src/keyman/ldml-keyboard/ldml-keyboard-xml-reader.ts
index 31ecdd50a6..07b2a95994 100644
--- a/developer/src/kmldmlc/src/keyman/ldml-keyboard/ldml-keyboard-xml-reader.ts
+++ b/developer/src/kmldmlc/src/keyman/ldml-keyboard/ldml-keyboard-xml-reader.ts
@@ -1,6 +1,8 @@
 import * as xml2js from 'xml2js';
 import LDMLKeyboardXMLSourceFile from './ldml-keyboard-xml';
 import CompilerCallbacks from '../compiler/callbacks';
+import Ajv from 'ajv';
+import { CompilerErrors } from '../compiler/errors';
 
 export default class LDMLKeyboardXMLSourceFileReader {
   private readonly callbacks: CompilerCallbacks;
@@ -16,7 +18,14 @@ export default class LDMLKeyboardXMLSourceFileReader {
    */
   private boxArrays(source: any) {
     let box = (o: any, x: string) => {
-      if(typeof o == 'object' && !Array.isArray(o[x])) o[x] = [o[x]];
+      if(typeof o == 'object' && !Array.isArray(o[x])) {
+        if(o[x] === null || o[x] === undefined) {
+          o[x] = [];
+        }
+        else {
+          o[x] = [o[x]];
+        }
+      }
     }
 
     box(source?.keyboard, 'layerMaps');
@@ -36,6 +45,16 @@ export default class LDMLKeyboardXMLSourceFileReader {
     return source;
   }
 
+  public validate(source: LDMLKeyboardXMLSourceFile): LDMLKeyboardXMLSourceFile {
+    const schema = JSON.parse(this.callbacks.loadLdmlKeyboardSchema().toString('utf8'));
+    const ajv = new Ajv();
+    if(!ajv.validate(schema, source)) {
+      this.callbacks.reportMessage(CompilerErrors.InvalidFile(ajv.errorsText()));
+      return null;
+    }
+    return source;
+  }
+
   public loadFile(filename: string) {
     const buf = this.callbacks.loadFile(filename, filename);
     return this.load(buf);
@@ -47,11 +66,12 @@ export default class LDMLKeyboardXMLSourceFileReader {
       let parser = new xml2js.Parser({
         explicitArray: false,
         mergeAttrs: true,
+        emptyTag: {}
       });
       parser.parseString(file, (e: unknown, r: unknown) => { a = r as LDMLKeyboardXMLSourceFile });
       return a;
     })();
 
-    return this.boxArrays(source);
+    return this.validate(this.boxArrays(source));
   }
 }
\ No newline at end of file
diff --git a/developer/src/kmldmlc/src/kmldmlc.ts b/developer/src/kmldmlc/src/kmldmlc.ts
index a74116c6bc..067291e95d 100644
--- a/developer/src/kmldmlc/src/kmldmlc.ts
+++ b/developer/src/kmldmlc/src/kmldmlc.ts
@@ -46,6 +46,9 @@ class CompilerCallbacks {
   reportMessage(event: CompilerEvent): void {
     console.log(CompilerErrors.severityName(event.code) + ' ' + event.code.toString(16) + ': ' + event.message);
   }
+  loadLdmlKeyboardSchema(): Buffer {
+    return fs.readFileSync(path.join(__dirname, 'ldml-keyboard.schema.json'));
+  }
 }
 
 function compileKeyboard(inputFilename: string): Uint8Array {
diff --git a/developer/src/kmldmlc/test/fixtures/invalid-structure-per-dtd.xml b/developer/src/kmldmlc/test/fixtures/invalid-structure-per-dtd.xml
new file mode 100644
index 0000000000..cb2a42e1fc
--- /dev/null
+++ b/developer/src/kmldmlc/test/fixtures/invalid-structure-per-dtd.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+  DOCTYPE keyboard SYSTEM "../../../../../resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.dtd"
+  Disabling doctype for this invalid file, not used by compiler, and avoids complaints in IDEs etc.
+-->
+<keyboard locale="mt" conformsTo="techpreview">
+</keyboard>
\ No newline at end of file
diff --git a/developer/src/kmldmlc/test/helpers/index.ts b/developer/src/kmldmlc/test/helpers/index.ts
index 79b7e88ce2..8d698af76a 100644
--- a/developer/src/kmldmlc/test/helpers/index.ts
+++ b/developer/src/kmldmlc/test/helpers/index.ts
@@ -29,6 +29,11 @@ export class CompilerCallbacks {
   reportMessage(event: CompilerEvent): void {
     this.messages.push(event);
   }
+  loadLdmlKeyboardSchema(): Buffer {
+    // Relative paths phooey!
+    return fs.readFileSync(path.join(__dirname, '..', '..', '..', '..', '..', '..',
+      'resources', 'standards-data', 'ldml-keyboards', 'techpreview', 'ldml-keyboard.schema.json'));
+  }
 }
 
 export function loadSectionFixture(compilerClass: typeof SectionCompiler, filename: string, callbacks: CompilerCallbacks): Section {
diff --git a/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts b/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
new file mode 100644
index 0000000000..3f84cce011
--- /dev/null
+++ b/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
@@ -0,0 +1,19 @@
+import 'mocha';
+import {assert} from 'chai';
+import {CompilerCallbacks, makePathToFixture} from '../helpers/index';
+import LDMLKeyboardXMLSourceFileReader from '../../src/keyman/ldml-keyboard/ldml-keyboard-xml-reader';
+import { CompilerErrors } from '../../src/keyman/compiler/errors';
+
+describe('ldml keyboard xml reader tests', function() {
+  this.slow(500); // 0.5 sec -- json schema validation takes a while
+
+  it("should fail to load files that don't conform to DTD", function() {
+    const inputFilename = makePathToFixture('invalid-structure-per-dtd.xml');
+    const callbacks = new CompilerCallbacks();
+    let reader = new LDMLKeyboardXMLSourceFileReader(callbacks);
+    const source = reader.loadFile(inputFilename);
+    assert.isNull(source);
+    assert.equal(callbacks.messages.length, 1);
+    assert.deepEqual(callbacks.messages[0], CompilerErrors.InvalidFile("data/keyboard must have required property 'names'"));
+  });
+});
\ No newline at end of file
diff --git a/developer/src/kmldmlc/test/test-compiler-e2e.ts b/developer/src/kmldmlc/test/test-compiler-e2e.ts
index 81280ff667..6f9f12b5f8 100644
--- a/developer/src/kmldmlc/test/test-compiler-e2e.ts
+++ b/developer/src/kmldmlc/test/test-compiler-e2e.ts
@@ -30,6 +30,8 @@ function compileKeyboard(inputFilename: string): Uint8Array {
 }
 
 describe('compiler-tests', function() {
+  this.slow(500); // 0.5 sec -- json schema validation takes a while
+
   it('should-build-fixtures', async function() {
     // Let's build basic.xml
     // It should match basic.kmx (built from basic.txt)
diff --git a/developer/src/kmldmlc/test/test-loca.ts b/developer/src/kmldmlc/test/test-loca.ts
index 5bc931a556..93f9e9d63a 100644
--- a/developer/src/kmldmlc/test/test-loca.ts
+++ b/developer/src/kmldmlc/test/test-loca.ts
@@ -6,6 +6,8 @@ import { Loca } from '../src/keyman/kmx/kmx-plus';
 import { CompilerErrors } from '../src/keyman/compiler/errors';
 
 describe('loca', function () {
+  this.slow(500); // 0.5 sec -- json schema validation takes a while
+
   it('should compile minimal loca data', function() {
     const callbacks = new CompilerCallbacks();
     let loca = loadSectionFixture(LocaCompiler, 'sections/loca/minimal.xml', callbacks) as Loca;
diff --git a/developer/src/kmldmlc/test/test-meta.ts b/developer/src/kmldmlc/test/test-meta.ts
index 715d1a17a8..ddfd0aea86 100644
--- a/developer/src/kmldmlc/test/test-meta.ts
+++ b/developer/src/kmldmlc/test/test-meta.ts
@@ -6,6 +6,8 @@ import { KeyboardSettings, Meta } from '../src/keyman/kmx/kmx-plus';
 import { CompilerErrors } from '../src/keyman/compiler/errors';
 
 describe('meta', function () {
+  this.slow(500); // 0.5 sec -- json schema validation takes a while
+
   it('should compile minimal metadata', function() {
     const callbacks = new CompilerCallbacks();
     let meta = loadSectionFixture(MetaCompiler, 'sections/meta/minimal.xml', callbacks) as Meta;
diff --git a/package-lock.json b/package-lock.json
index 00d7ed72f7..5ad4edfda9 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -473,6 +473,7 @@
       "name": "@keymanapp/ldml-keyboard-compiler",
       "license": "MIT",
       "dependencies": {
+        "ajv": "^8.11.0",
         "commander": "^3.0.0",
         "crc-32": "^1.2.2",
         "restructure": "^3.0.0",
@@ -506,6 +507,21 @@
       "integrity": "sha512-F0KIgDJfy2nA3zMLmWGKxcH2ZVEtCZXHHdOQs2gSaQ27+lNeEfGxzkIw90aXswATX7AZ33tahPbzy6KAfUreVw==",
       "dev": true
     },
+    "developer/src/kmldmlc/node_modules/ajv": {
+      "version": "8.11.0",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.11.0.tgz",
+      "integrity": "sha512-wGgprdCvMalC0BztXvitD2hC04YffAvtsUn93JbGXYLAtCUO4xd17mCCZQxUOItiBwZvJScWo8NIvQMQ71rdpg==",
+      "dependencies": {
+        "fast-deep-equal": "^3.1.1",
+        "json-schema-traverse": "^1.0.0",
+        "require-from-string": "^2.0.2",
+        "uri-js": "^4.2.2"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/epoberezkin"
+      }
+    },
     "developer/src/kmldmlc/node_modules/ansi-styles": {
       "version": "3.2.1",
       "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
@@ -556,6 +572,11 @@
         "node": ">=4"
       }
     },
+    "developer/src/kmldmlc/node_modules/json-schema-traverse": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
+      "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug=="
+    },
     "developer/src/kmldmlc/node_modules/supports-color": {
       "version": "5.5.0",
       "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
@@ -3340,8 +3361,7 @@
     "node_modules/fast-deep-equal": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
-      "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
-      "optional": true
+      "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q=="
     },
     "node_modules/fast-json-stable-stringify": {
       "version": "2.1.0",
@@ -5580,7 +5600,6 @@
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.1.1.tgz",
       "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==",
-      "optional": true,
       "engines": {
         "node": ">=6"
       }
@@ -5747,6 +5766,14 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/require-from-string": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
+      "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/require-main-filename": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/require-main-filename/-/require-main-filename-2.0.0.tgz",
@@ -6600,7 +6627,6 @@
       "version": "4.4.1",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
       "integrity": "sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==",
-      "optional": true,
       "dependencies": {
         "punycode": "^2.1.0"
       }
@@ -7781,6 +7807,7 @@
         "@types/mocha": "^5.2.7",
         "@types/node": "^10.14.6",
         "@types/xml2js": "^0.4.5",
+        "ajv": "^8.11.0",
         "chai": "^4.3.4",
         "chalk": "^2.4.2",
         "commander": "^3.0.0",
@@ -7804,6 +7831,17 @@
           "integrity": "sha512-F0KIgDJfy2nA3zMLmWGKxcH2ZVEtCZXHHdOQs2gSaQ27+lNeEfGxzkIw90aXswATX7AZ33tahPbzy6KAfUreVw==",
           "dev": true
         },
+        "ajv": {
+          "version": "8.11.0",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.11.0.tgz",
+          "integrity": "sha512-wGgprdCvMalC0BztXvitD2hC04YffAvtsUn93JbGXYLAtCUO4xd17mCCZQxUOItiBwZvJScWo8NIvQMQ71rdpg==",
+          "requires": {
+            "fast-deep-equal": "^3.1.1",
+            "json-schema-traverse": "^1.0.0",
+            "require-from-string": "^2.0.2",
+            "uri-js": "^4.2.2"
+          }
+        },
         "ansi-styles": {
           "version": "3.2.1",
           "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-3.2.1.tgz",
@@ -7845,6 +7883,11 @@
           "integrity": "sha512-sKJf1+ceQBr4SMkvQnBDNDtf4TXpVhVGateu0t918bl30FnbE2m4vNLX+VWe/dpjlb+HugGYzW7uQXH98HPEYw==",
           "dev": true
         },
+        "json-schema-traverse": {
+          "version": "1.0.0",
+          "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
+          "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug=="
+        },
         "supports-color": {
           "version": "5.5.0",
           "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
@@ -9981,8 +10024,7 @@
     "fast-deep-equal": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
-      "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
-      "optional": true
+      "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q=="
     },
     "fast-json-stable-stringify": {
       "version": "2.1.0",
@@ -11747,8 +11789,7 @@
     "punycode": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.1.1.tgz",
-      "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==",
-      "optional": true
+      "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A=="
     },
     "q": {
       "version": "1.5.1",
@@ -11874,6 +11915,11 @@
       "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
       "integrity": "sha1-jGStX9MNqxyXbiNE/+f3kqam30I="
     },
+    "require-from-string": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
+      "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw=="
+    },
     "require-main-filename": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/require-main-filename/-/require-main-filename-2.0.0.tgz",
@@ -12520,7 +12566,6 @@
       "version": "4.4.1",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
       "integrity": "sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==",
-      "optional": true,
       "requires": {
         "punycode": "^2.1.0"
       }
diff --git a/resources/standards-data/ldml-keyboards/readme.md b/resources/standards-data/ldml-keyboards/readme.md
index 826f6d5dd5..bcd04b1109 100644
--- a/resources/standards-data/ldml-keyboards/readme.md
+++ b/resources/standards-data/ldml-keyboards/readme.md
@@ -12,4 +12,13 @@ That will very roughly correspond to <https://github.com/unicode-org/cldr/tree/k
 Each directory contains:
 
 - `ldmlKeyboard.dtd` - the DTD file
+- `ldmlKeyboard.xsd` - the XSD file, automatically converted from the DTD using
+  Visual Studio, hand tweaked as necessary
+- `ldml-keyboard.schema.json` - the JSON schema file, automatically converted
+  from the XSD using xsd2json (https://github.com/Mermade/jgeXml), hand tweaked
+  as necessary:
+    - change toplevel "id" to "$id"
+    - add "type": "object" to /keyboard
+    - change /keyboard/keys/key type to "array"
+
 - `imports/` - the importable data files (TODO-LDML)
diff --git a/resources/standards-data/ldml-keyboards/techpreview/ldml-keyboard.schema.json b/resources/standards-data/ldml-keyboards/techpreview/ldml-keyboard.schema.json
new file mode 100644
index 0000000000..fb02a14e8e
--- /dev/null
+++ b/resources/standards-data/ldml-keyboards/techpreview/ldml-keyboard.schema.json
@@ -0,0 +1,677 @@
+{
+  "title": "techpreview/ldmlKeyboard.xsd",
+  "$schema": "http://json-schema.org/schema#",
+  "$id": "http://tempuri.org/ldmlKeyboard",
+  "type": "object",
+  "properties": {
+    "keyboard": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "locales": {
+          "$ref": "#/definitions/locales"
+        },
+        "version": {
+          "$ref": "#/definitions/version"
+        },
+        "info": {
+          "$ref": "#/definitions/info"
+        },
+        "names": {
+          "$ref": "#/definitions/names"
+        },
+        "settings": {
+          "$ref": "#/definitions/settings"
+        },
+        "vkeyMaps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/vkeyMaps"
+          }
+        },
+        "displayMap": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/displayMap"
+          }
+        },
+        "keys": {
+          "$ref": "#/definitions/keys"
+        },
+        "layerMaps": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/layerMaps"
+          }
+        },
+        "transforms": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/transforms"
+          }
+        },
+        "reorders": {
+          "$ref": "#/definitions/reorders"
+        },
+        "backspaces": {
+          "$ref": "#/definitions/backspaces"
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "locale": {
+          "type": "string"
+        },
+        "conformsTo": {
+          "type": "string",
+          "enum": [
+            "techpreview"
+          ]
+        }
+      },
+      "required": [
+        "names",
+        "keys",
+        "locale",
+        "conformsTo"
+      ],
+      "additionalProperties": false
+    }
+  },
+  "required": [
+    "keyboard"
+  ],
+  "additionalProperties": false,
+  "definitions": {
+    "import": {
+      "type": "object",
+      "properties": {
+        "path": {
+          "type": "string"
+        },
+        "base": {
+          "type": "string",
+          "enum": [
+            "cldr"
+          ]
+        }
+      },
+      "required": [
+        "path"
+      ],
+      "additionalProperties": false
+    },
+    "locales": {
+      "type": "object",
+      "properties": {
+        "locale": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/locale"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "locale": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "id"
+      ],
+      "additionalProperties": false
+    },
+    "version": {
+      "type": "object",
+      "properties": {
+        "number": {
+          "type": "string"
+        },
+        "cldrVersion": {
+          "type": "string",
+          "enum": [
+            "techpreview"
+          ]
+        }
+      },
+      "additionalProperties": false
+    },
+    "info": {
+      "type": "object",
+      "properties": {
+        "author": {
+          "type": "string"
+        },
+        "normalization": {
+          "type": "string"
+        },
+        "layout": {
+          "type": "string"
+        },
+        "indicator": {
+          "type": "string"
+        }
+      },
+      "additionalProperties": false
+    },
+    "names": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "name": {
+          "type": "array",
+          "minItems": 1,
+          "items": {
+            "$ref": "#/definitions/name"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        }
+      },
+      "required": [
+        "name"
+      ],
+      "additionalProperties": false
+    },
+    "name": {
+      "type": "object",
+      "properties": {
+        "value": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "value"
+      ],
+      "additionalProperties": false
+    },
+    "special": {
+      "type": "string"
+    },
+    "settings": {
+      "type": "object",
+      "properties": {
+        "fallback": {
+          "type": "string",
+          "enum": [
+            "omit"
+          ]
+        },
+        "transformFailure": {
+          "type": "string",
+          "enum": [
+            "omit"
+          ]
+        },
+        "transformPartial": {
+          "type": "string",
+          "enum": [
+            "hide"
+          ]
+        }
+      },
+      "additionalProperties": false
+    },
+    "vkeyMaps": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "vkeyMap": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/vkeyMap"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "vkeyMap": {
+      "type": "object",
+      "properties": {
+        "from": {
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "from",
+        "to"
+      ],
+      "additionalProperties": false
+    },
+    "displayMap": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "display": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/display"
+          }
+        },
+        "displayOptions": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/displayOptions"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "display": {
+      "type": "object",
+      "properties": {
+        "to": {
+          "type": "string"
+        },
+        "display": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "to",
+        "display"
+      ],
+      "additionalProperties": false
+    },
+    "displayOptions": {
+      "type": "object",
+      "properties": {
+        "baseCharacter": {
+          "type": "string"
+        }
+      },
+      "additionalProperties": false
+    },
+    "keys": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "key": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/key"
+          }
+        },
+        "flicks": {
+          "$ref": "#/definitions/flicks"
+        }
+      },
+      "additionalProperties": false
+    },
+    "key": {
+      "type": "object",
+      "properties": {
+        "id": {
+          "type": "string"
+        },
+        "flicks": {
+          "type": "string"
+        },
+        "gap": {
+          "type": "string",
+          "enum": [
+            "true"
+          ]
+        },
+        "to": {
+          "type": "string"
+        },
+        "longPress": {
+          "type": "string"
+        },
+        "longPressDefault": {
+          "type": "string"
+        },
+        "multitap": {
+          "type": "string"
+        },
+        "switch": {
+          "type": "string"
+        },
+        "transform": {
+          "type": "string",
+          "enum": [
+            "no"
+          ]
+        },
+        "width": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "id"
+      ],
+      "additionalProperties": false
+    },
+    "flicks": {
+      "type": "object",
+      "properties": {
+        "flick": {
+          "type": "array",
+          "minItems": 1,
+          "items": {
+            "$ref": "#/definitions/flick"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "id": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "flick",
+        "id"
+      ],
+      "additionalProperties": false
+    },
+    "flick": {
+      "type": "object",
+      "properties": {
+        "directions": {
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "directions",
+        "to"
+      ],
+      "additionalProperties": false
+    },
+    "layerMaps": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "layerMap": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/layerMap"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "form": {
+          "type": "string",
+          "enum": [
+            "hardware",
+            "touch"
+          ]
+        },
+        "minDeviceWidthMM": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "form"
+      ],
+      "additionalProperties": false
+    },
+    "layerMap": {
+      "type": "object",
+      "properties": {
+        "row": {
+          "type": "array",
+          "minItems": 1,
+          "items": {
+            "$ref": "#/definitions/row"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "id": {
+          "type": "string"
+        },
+        "modifier": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "row"
+      ],
+      "additionalProperties": false
+    },
+    "row": {
+      "type": "object",
+      "properties": {
+        "keys": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "keys"
+      ],
+      "additionalProperties": false
+    },
+    "transforms": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "transform": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/transform"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        },
+        "type": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "type"
+      ],
+      "additionalProperties": false
+    },
+    "transform": {
+      "type": "object",
+      "properties": {
+        "before": {
+          "type": "string"
+        },
+        "from": {
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        },
+        "error": {
+          "type": "string",
+          "enum": [
+            "fail"
+          ]
+        }
+      },
+      "required": [
+        "from",
+        "to"
+      ],
+      "additionalProperties": false
+    },
+    "reorders": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "reorder": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/reorder"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "reorder": {
+      "type": "object",
+      "properties": {
+        "before": {
+          "type": "string"
+        },
+        "from": {
+          "type": "string"
+        },
+        "order": {
+          "type": "string"
+        },
+        "tertiary": {
+          "type": "string"
+        },
+        "tertiary_base": {
+          "type": "string"
+        },
+        "prebase": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "from"
+      ],
+      "additionalProperties": false
+    },
+    "backspaces": {
+      "type": "object",
+      "properties": {
+        "import": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/import"
+          }
+        },
+        "backspace": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/backspace"
+          }
+        },
+        "special": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/special"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "backspace": {
+      "type": "object",
+      "properties": {
+        "before": {
+          "type": "string"
+        },
+        "from": {
+          "type": "string"
+        },
+        "to": {
+          "type": "string"
+        },
+        "error": {
+          "type": "string",
+          "enum": [
+            "fail"
+          ]
+        }
+      },
+      "required": [
+        "from"
+      ],
+      "additionalProperties": false
+    }
+  }
+}
\ No newline at end of file
diff --git a/resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.xsd b/resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.xsd
new file mode 100644
index 0000000000..9e9e070421
--- /dev/null
+++ b/resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.xsd
@@ -0,0 +1,304 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- generated via Visual Studio from ldmlKeyboard.dtd -->
+<xs:schema xmlns="http://tempuri.org/ldmlKeyboard" elementFormDefault="qualified" targetNamespace="http://tempuri.org/ldmlKeyboard" xmlns:xs="http://www.w3.org/2001/XMLSchema">
+  <xs:element name="keyboard">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="locales" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="version" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="info" />
+        <xs:element ref="names" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="settings" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="vkeyMaps" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="displayMap" />
+        <xs:element ref="keys" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="layerMaps" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="transforms" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="reorders" />
+        <xs:element minOccurs="0" maxOccurs="1" ref="backspaces" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+      <xs:attribute name="locale" type="xs:string" use="required" />
+      <xs:attribute name="conformsTo" use="required">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="techpreview" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="import">
+    <xs:complexType>
+      <xs:attribute name="path" type="xs:string" use="required" />
+      <xs:attribute name="base">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="cldr" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="locales">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="locale" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="locale">
+    <xs:complexType>
+      <xs:attribute name="id" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="version">
+    <xs:complexType>
+      <xs:attribute name="number" type="xs:string" />
+      <xs:attribute fixed="techpreview" name="cldrVersion" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="info">
+    <xs:complexType>
+      <xs:attribute name="author" type="xs:string" />
+      <xs:attribute name="normalization" type="xs:string" />
+      <xs:attribute name="layout" type="xs:string" />
+      <xs:attribute name="indicator" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="names">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="1" maxOccurs="unbounded" ref="name" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="name">
+    <xs:complexType>
+      <xs:attribute name="value" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="special">
+    <xs:complexType mixed="true">
+      <xs:sequence>
+        <xs:any minOccurs="0" maxOccurs="unbounded" namespace="##any" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="settings">
+    <xs:complexType>
+      <xs:attribute name="fallback">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="omit" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+      <xs:attribute name="transformFailure">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="omit" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+      <xs:attribute name="transformPartial">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="hide" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="vkeyMaps">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="vkeyMap" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="vkeyMap">
+    <xs:complexType>
+      <xs:attribute name="from" type="xs:string" use="required" />
+      <xs:attribute name="to" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="displayMap">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="display" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="displayOptions" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="display">
+    <xs:complexType>
+      <xs:attribute name="to" type="xs:string" use="required" />
+      <xs:attribute name="display" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="displayOptions">
+    <xs:complexType>
+      <xs:attribute name="baseCharacter" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="keys">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:choice minOccurs="0" maxOccurs="unbounded">
+          <xs:element ref="key" />
+          <xs:element ref="flicks" />
+        </xs:choice>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="key">
+    <xs:complexType>
+      <xs:attribute name="id" type="xs:string" use="required" />
+      <xs:attribute name="flicks" type="xs:NMTOKEN" />
+      <xs:attribute name="gap">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="true" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+      <xs:attribute name="to" type="xs:string" />
+      <xs:attribute name="longPress" type="xs:string" />
+      <xs:attribute name="longPressDefault" type="xs:string" />
+      <xs:attribute name="multitap" type="xs:string" />
+      <xs:attribute name="switch" type="xs:NMTOKEN" />
+      <xs:attribute name="transform">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="no" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+      <xs:attribute name="width" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="flicks">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="1" maxOccurs="unbounded" ref="flick" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+      <xs:attribute name="id" type="xs:NMTOKEN" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="flick">
+    <xs:complexType>
+      <xs:attribute name="directions" type="xs:NMTOKENS" use="required" />
+      <xs:attribute name="to" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="layerMaps">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="layerMap" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+      <xs:attribute name="form" use="required">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="hardware" />
+            <xs:enumeration value="touch" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+      <xs:attribute name="minDeviceWidthMM" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="layerMap">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="1" maxOccurs="unbounded" ref="row" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+      <xs:attribute name="id" type="xs:NMTOKEN" />
+      <xs:attribute name="modifier" type="xs:NMTOKEN" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="row">
+    <xs:complexType>
+      <xs:attribute name="keys" type="xs:NMTOKENS" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="transforms">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="transform" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+      <xs:attribute name="type" type="xs:string" use="required" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="transform">
+    <xs:complexType>
+      <xs:attribute name="before" type="xs:string" />
+      <xs:attribute name="from" type="xs:string" use="required" />
+      <xs:attribute name="to" type="xs:string" use="required" />
+      <xs:attribute name="error">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="fail" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="reorders">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="reorder" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="reorder">
+    <xs:complexType>
+      <xs:attribute name="before" type="xs:string" />
+      <xs:attribute name="from" type="xs:string" use="required" />
+      <xs:attribute name="order" type="xs:string" />
+      <xs:attribute name="tertiary" type="xs:string" />
+      <xs:attribute name="tertiary_base" type="xs:string" />
+      <xs:attribute name="prebase" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="backspaces">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="import" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="backspace" />
+        <xs:element minOccurs="0" maxOccurs="unbounded" ref="special" />
+      </xs:sequence>
+    </xs:complexType>
+  </xs:element>
+  <xs:element name="backspace">
+    <xs:complexType>
+      <xs:attribute name="before" type="xs:string" />
+      <xs:attribute name="from" type="xs:string" use="required" />
+      <xs:attribute name="to" type="xs:string" />
+      <xs:attribute name="error">
+        <xs:simpleType>
+          <xs:restriction base="xs:NMTOKEN">
+            <xs:enumeration value="fail" />
+          </xs:restriction>
+        </xs:simpleType>
+      </xs:attribute>
+    </xs:complexType>
+  </xs:element>
+</xs:schema>
\ No newline at end of file

From 918d261f99fc105993588d013a1ae75ce08bc6c7 Mon Sep 17 00:00:00 2001
From: Marc Durdin <marc@durdin.net>
Date: Fri, 2 Sep 2022 08:01:48 +1000
Subject: [PATCH 2/2] feat(developer): add conformsTo validity unit test

This is reasonably random, but wanted to add another test for content
rather than structure, just to verify that the DTD-XSD-jsonschema
translation is doing the right thing according to what we expect.

Looking good.
---
 .../test/fixtures/invalid-conforms-to.xml     | 19 +++++++++++++++++++
 .../test-ldml-keyboard-xml-reader.ts          | 11 +++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 developer/src/kmldmlc/test/fixtures/invalid-conforms-to.xml

diff --git a/developer/src/kmldmlc/test/fixtures/invalid-conforms-to.xml b/developer/src/kmldmlc/test/fixtures/invalid-conforms-to.xml
new file mode 100644
index 0000000000..ba806bdcc5
--- /dev/null
+++ b/developer/src/kmldmlc/test/fixtures/invalid-conforms-to.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+  DOCTYPE keyboard SYSTEM "../../../../../resources/standards-data/ldml-keyboards/techpreview/ldmlKeyboard.dtd"
+  Disabling doctype for this invalid file, not used by compiler, and avoids complaints in IDEs etc.
+-->
+<keyboard locale="mt" conformsTo="nothing-anyone-ever-heard-of">
+  <info author="srl295" indicator="🙀" layout="qwerty" normalization="NFC" />
+
+  <names>
+    <name value="TestKbd" />
+  </names>
+
+  <keys>
+    <key id="hmaqtua" to="ħ" />
+    <key id="that" to="ថា" />
+  </keys>
+
+</keyboard>
\ No newline at end of file
diff --git a/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts b/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
index 3f84cce011..b3803c07ac 100644
--- a/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
+++ b/developer/src/kmldmlc/test/ldml-keyboard/test-ldml-keyboard-xml-reader.ts
@@ -16,4 +16,15 @@ describe('ldml keyboard xml reader tests', function() {
     assert.equal(callbacks.messages.length, 1);
     assert.deepEqual(callbacks.messages[0], CompilerErrors.InvalidFile("data/keyboard must have required property 'names'"));
   });
+
+  it("should fail to load files with an invalid conformsTo", function() {
+    const inputFilename = makePathToFixture('invalid-conforms-to.xml');
+    const callbacks = new CompilerCallbacks();
+    let reader = new LDMLKeyboardXMLSourceFileReader(callbacks);
+    const source = reader.loadFile(inputFilename);
+    assert.isNull(source);
+    assert.equal(callbacks.messages.length, 1);
+    assert.deepEqual(callbacks.messages[0], CompilerErrors.InvalidFile("data/keyboard/conformsTo must be equal to one of the allowed values"));
+  });
+
 });
\ No newline at end of file