diff --git a/developer/src/kmldmlc/test/test-compiler-e2e.ts b/developer/src/kmldmlc/test/test-compiler-e2e.ts
index 6f9f12b5f8..145bf2a90e 100644
--- a/developer/src/kmldmlc/test/test-compiler-e2e.ts
+++ b/developer/src/kmldmlc/test/test-compiler-e2e.ts
@@ -7,25 +7,32 @@ import Compiler from '../src/keyman/compiler/compiler';
 import KMXBuilder from '../src/keyman/kmx/kmx-builder';
 import {CompilerCallbacks, makePathToFixture} from './helpers/index';
 
+function checkMessages(callbacks: CompilerCallbacks) {
+  if(callbacks.messages.length > 0) {
+    console.log(callbacks.messages);
+  }
+  assert.isEmpty(callbacks.messages);
+}
+
 function compileKeyboard(inputFilename: string): Uint8Array {
   const callbacks = new CompilerCallbacks();
   const k = new Compiler(callbacks);
-  let source = k.load(inputFilename);
-  if(!source) {
-    return null;
-  }
-  if(!k.validate(source)) {
-    return null;
-  }
-  let kmx = k.compile(source);
-  if(!kmx) {
-    return null;
-  }
+  const source = k.load(inputFilename);
+  checkMessages(callbacks);
+  assert.isNotNull(source, 'k.load should not have returned null');
+
+  const valid = k.validate(source);
+  checkMessages(callbacks);
+  assert.isTrue(valid, 'k.validate should not have failed');
+
+  const kmx = k.compile(source);
+  checkMessages(callbacks);
+  assert.isNotNull(kmx, 'k.compile should not have returned null');
 
   // Use the builder to generate the binary output file
-  let builder = new KMXBuilder(kmx, true);
-  let result = builder.compile();
-  assert(callbacks.messages.length == 0);
+  const builder = new KMXBuilder(kmx, true);
+  const result = builder.compile();
+  checkMessages(callbacks);
   return result;
 }
 
diff --git a/developer/src/kmldmlc/test/test-messages.ts b/developer/src/kmldmlc/test/test-messages.ts
new file mode 100644
index 0000000000..831bb1e758
--- /dev/null
+++ b/developer/src/kmldmlc/test/test-messages.ts
@@ -0,0 +1,74 @@
+import 'mocha';
+import {assert, expect} from 'chai';
+import { CompilerErrorSeverity, CompilerMessages } from '../src/keyman/compiler/messages';
+
+const toTitleCase = (s: string) => s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
+
+//
+// The purpose of these tests is to ensure that our slightly WET constant
+// definitions for compiler errors are consistent in their usage:
+//
+//   * that names are consistent between the message functions and constants
+//   * that constants have unique codes
+//   * that constants have the right error mask for their type
+//
+// This means we don't have to worry about DRYing out the constants, which would
+// probably require us to have a preprocessing step, which has its own negatives.
+//
+
+describe('compiler messages', function () {
+  it('each compiler message function has a corresponding constant', function() {
+    let keys = Object.keys(CompilerMessages);
+
+    const m = CompilerMessages as Record<string,any>;
+
+    for(let key of keys) {
+      if(key == 'severityName') {
+        // any helper functions we skip here
+        continue;
+      }
+
+      if(typeof m[key] == 'function') {
+        const o = /^(Info|Hint|Warning|Error|Fatal)_([A-Za-z0-9_]+)$/.exec(key);
+        expect(o).to.be.instanceOf(Array);
+
+        const c = o[1].toUpperCase() + '_' + o[2];
+        expect(m[c]).to.be.a('number', `Expected constant name ${c} to exist`);
+
+        let v = m[key]('','','','','','','','','','','','' /* ignore arguments*/);
+        expect(v.code).to.equal(m[c], `Function ${key} returns the wrong code`);
+      }
+      else if(typeof m[key] == 'number') {
+        const o = /^(INFO|HINT|WARNING|ERROR|FATAL)_([A-Za-z0-9_]+)$/.exec(key);
+        expect(o).to.be.instanceOf(Array);
+
+        const f = toTitleCase(o[1]) + '_' + o[2];
+        expect(m[f]).to.be.a('function', `Expected function name ${f} to exist`);
+      } else {
+        assert.fail(`Unexepected compiler message member ${key}`);
+      }
+    }
+  });
+
+  it('each compiler message constant to be have the right mask and be unique', function() {
+    let keys = Object.keys(CompilerMessages);
+
+    const m = CompilerMessages as Record<string,any>;
+
+    let codes: number[] = [];
+
+    for(let key of keys) {
+      if(typeof m[key] == 'number') {
+        const o = /^(INFO|HINT|WARNING|ERROR|FATAL)_([A-Za-z0-9_]+)$/.exec(key);
+        expect(o).to.be.instanceOf(Array);
+
+        const mask = CompilerMessages.severityName(m[key]);
+        expect(o[1]).to.equal(mask, `Mask value for ${key} does not match`);
+
+        const code = m[key] & CompilerErrorSeverity.Error_Mask;
+        expect(codes).to.not.contain(code, `Constant value ${key} is not unique`);
+        codes.push(code);
+      }
+    }
+  });
+});
\ No newline at end of file