[FSSDK-12933] Refactor message generator to use TS compiler API

.github/workflows/javascript.yml

@@ -115,6 +115,21 @@ jobs:
   #       npm install
   #       npm run test-ci
 
+  generate_messages_test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Node
+      uses: actions/setup-node@v3
+      with:
+        node-version: 20
+        cache-dependency-path: ./package-lock.json
+        cache: 'npm'
+    - name: Test generate-messages script
+      run: |
+        npm install
+        node scripts/test-generate-messages.js
+
   unit_tests:
     runs-on: ubuntu-latest
     strategy:

package.json

@@ -78,7 +78,7 @@
     "coveralls": "nyc --reporter=lcov npm test",
     "prepare": "npm run build",
     "prepublishOnly": "npm test",
-    "genmsg": "jiti message_generator ./lib/message/error_message.ts ./lib/message/log_message.ts",
+    "genmsg": "./scripts/generate-messages.js ./lib/message/error_message.ts ./lib/message/log_message.ts",
     "test-typescript": "node ./scripts/run-ts-example.js",
     "test-commonjs": "node ./scripts/run-cjs-example.js"
   },
@@ -126,7 +126,6 @@
     "eslint-plugin-local-rules": "^3.0.2",
     "eslint-plugin-prettier": "^3.1.2",
     "happy-dom": "^20.0.11",
-    "jiti": "^2.4.1",
     "minimatch": "^9.0.5",
     "mocha": "^10.2.0",
     "mocha-lcov-reporter": "^1.3.0",

scripts/generate-messages.js

@@ -0,0 +1,121 @@
+#!/usr/bin/env node
+
+/**
+ * Copyright 2026, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const ts = require('typescript');
+const fs = require('fs');
+const path = require('path');
+
+function extractMessages(filePath) {
+  const source = fs.readFileSync(filePath, 'utf-8');
+  const sourceFile = ts.createSourceFile(
+    filePath,
+    source,
+    ts.ScriptTarget.Latest,
+    true,
+  );
+
+  const exports = [];
+
+  for (const statement of sourceFile.statements) {
+    if (!ts.isVariableStatement(statement)) continue;
+
+    const hasExport = statement.modifiers?.some(
+      (m) => m.kind === ts.SyntaxKind.ExportKeyword,
+    );
+    if (!hasExport) continue;
+
+    for (const decl of statement.declarationList.declarations) {
+      const name = decl.name.getText(sourceFile);
+      if (name === 'messages' || name === '__platforms') continue;
+      if (!decl.initializer || !ts.isStringLiteral(decl.initializer)) continue;
+
+      exports.push({ name, value: decl.initializer.text });
+    }
+  }
+
+  return exports;
+}
+
+function buildOutputAst(exports) {
+  const { factory } = ts;
+  const statements = [];
+
+  exports.forEach((exp, i) => {
+    statements.push(
+      factory.createVariableStatement(
+        [factory.createModifier(ts.SyntaxKind.ExportKeyword)],
+        factory.createVariableDeclarationList(
+          [factory.createVariableDeclaration(exp.name, undefined, undefined, factory.createStringLiteral(String(i)))],
+          ts.NodeFlags.Const,
+        ),
+      ),
+    );
+  });
+
+  statements.push(
+    factory.createVariableStatement(
+      [factory.createModifier(ts.SyntaxKind.ExportKeyword)],
+      factory.createVariableDeclarationList(
+        [
+          factory.createVariableDeclaration(
+            'messages',
+            undefined,
+            undefined,
+            factory.createArrayLiteralExpression(
+              exports.map((exp) => factory.createStringLiteral(exp.value)),
+              true,
+            ),
+          ),
+        ],
+        ts.NodeFlags.Const,
+      ),
+    ),
+  );
+
+  return factory.createSourceFile(statements, factory.createToken(ts.SyntaxKind.EndOfFileToken), ts.NodeFlags.None);
+}
+
+function generate(filePath) {
+  const absPath = path.resolve(filePath);
+  const parsed = path.parse(absPath);
+  const genPath = path.join(parsed.dir, `${parsed.name}.gen${parsed.ext}`);
+
+  console.log('generating messages for:', absPath);
+
+  const exports = extractMessages(absPath);
+  const outputAst = buildOutputAst(exports);
+
+  const printer = ts.createPrinter({ newLine: ts.NewLineKind.LineFeed });
+  const output = printer.printFile(outputAst);
+
+  fs.writeFileSync(genPath, output, 'utf-8');
+  console.log('generated file path:', genPath);
+}
+
+const files = process.argv.slice(2);
+
+if (files.length === 0) {
+  console.error('Usage: generate-messages.js <file1.ts> [file2.ts] ...');
+  process.exit(1);
+}
+
+for (const file of files) {
+  generate(file);
+}
+
+console.log('successfully generated messages');

scripts/test-generate-messages.js

@@ -0,0 +1,90 @@
+#!/usr/bin/env node
+
+const assert = require('node:assert/strict');
+const { execFileSync } = require('node:child_process');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const ts = require('typescript');
+
+const SCRIPT = path.resolve(__dirname, 'generate-messages.js');
+
+const FILE1_EXPECTED = [
+  { name: 'HELLO', value: 'Hello, %s!' },
+  { name: 'GOODBYE', value: 'Goodbye, %s!' },
+  { name: 'WARNING', value: 'Warning: %s' },
+];
+
+const FILE2_EXPECTED = [
+  { name: 'ERR_NOT_FOUND', value: 'Resource %s not found' },
+  { name: 'ERR_TIMEOUT', value: 'Request timed out after %s ms' },
+  { name: 'ERR_INVALID', value: 'Invalid input: %s' },
+  { name: 'ERR_PERMISSION', value: 'Permission denied for %s' },
+];
+
+function buildFileContent(expected, { includeMessages = true, includePlatforms = false } = {}) {
+  let content = expected.map((e) => `export const ${e.name} = '${e.value}';`).join('\n');
+  if (includeMessages) content += `\n\nexport const messages: string[] = [];`;
+  if (includePlatforms) content += `\nexport const __platforms: string[] = ['__universal__'];`;
+  return content;
+}
+
+function compileAndLoad(tsPath) {
+  const source = fs.readFileSync(tsPath, 'utf-8');
+  const { outputText } = ts.transpileModule(source, {
+    compilerOptions: { module: ts.ModuleKind.CommonJS },
+  });
+  const jsPath = tsPath.replace(/\.ts$/, '.js');
+  fs.writeFileSync(jsPath, outputText, 'utf-8');
+  return require(jsPath);
+}
+
+function runTest() {
+  const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gen-msg-test-'));
+
+  try {
+    const file1 = path.join(tmpDir, 'file1.ts');
+    const file2 = path.join(tmpDir, 'file2.ts');
+    fs.writeFileSync(file1, buildFileContent(FILE1_EXPECTED, { includePlatforms: true }), 'utf-8');
+    fs.writeFileSync(file2, buildFileContent(FILE2_EXPECTED), 'utf-8');
+
+    execFileSync(process.execPath, [SCRIPT, file1, file2], { stdio: 'pipe' });
+
+    const genFile1 = path.join(tmpDir, 'file1.gen.ts');
+    const genFile2 = path.join(tmpDir, 'file2.gen.ts');
+    assert.ok(fs.existsSync(genFile1), 'file1.gen.ts should be created');
+    assert.ok(fs.existsSync(genFile2), 'file2.gen.ts should be created');
+
+    for (const [expected, genPath, label] of [
+      [FILE1_EXPECTED, genFile1, 'file1'],
+      [FILE2_EXPECTED, genFile2, 'file2'],
+    ]) {
+      const mod = compileAndLoad(genPath);
+
+      assert.ok(Array.isArray(mod.messages), `${label}: messages should be an array`);
+      assert.equal(mod.messages.length, expected.length,
+        `${label}: messages array length should be ${expected.length}, got ${mod.messages.length}`);
+
+      assert.equal(mod.__platforms, undefined, `${label}: __platforms should not be exported`);
+
+      const constantCount = Object.keys(mod).filter((k) => k !== 'messages').length;
+      assert.equal(constantCount, expected.length,
+        `${label}: should have ${expected.length} constants, got ${constantCount}`);
+
+      for (const exp of expected) {
+        assert.ok(exp.name in mod,
+          `${label}: constant "${exp.name}" should be present`);
+
+        const index = Number(mod[exp.name]);
+        assert.equal(mod.messages[index], exp.value,
+          `${label}: messages[${index}] should be "${exp.value}", got "${mod.messages[index]}"`);
+      }
+    }
+
+    console.log('All tests passed.');
+  } finally {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  }
+}
+
+runTest();