feat(jsii): allow customizing tsconfig.json file name (#3076)

In order to support environment in which users want to use the default name tsconfig.json for a different compiler configuration (e.g. configuration that includes both sources and test files), add a switch to the jsii compiler that allows customizing the name of the generated tsconfig.json file.

packages/jsii/bin/jsii.ts

@@ -64,6 +64,11 @@ const warningTypes = Object.keys(enabledWarnings);
             type: 'boolean',
             default: false,
             desc: '[EXPERIMENTAL] Injects warning statements for all deprecated elements, to be printed at runtime',
+          })
+          .option('generate-tsconfig', {
+            type: 'string',
+            default: 'tsconfig.json',
+            desc: 'Name of the typescript configuration file to generate with compiler settings',
           }),
     )
     .option('verbose', {
@@ -108,6 +113,7 @@ const warningTypes = Object.keys(enabledWarnings);
     failOnWarnings: argv['fail-on-warnings'],
     stripDeprecated: argv['strip-deprecated'],
     addDeprecationWarnings: argv['add-deprecation-warnings'],
+    generateTypeScriptConfig: argv['generate-tsconfig'],
   });
 
   const emitResult = await (argv.watch ? compiler.watch() : compiler.emit());

packages/jsii/lib/compiler.ts

@@ -54,6 +54,11 @@ export interface CompilerOptions {
   stripDeprecated?: boolean;
   /** Whether to add warnings for deprecated elements */
   addDeprecationWarnings?: boolean;
+  /**
+   * The name of the tsconfig file to generate
+   * @default "tsconfig.json"
+   */
+  generateTypeScriptConfig?: string;
 }
 
 export interface TypescriptConfig {
@@ -79,9 +84,11 @@ export class Compiler implements Emitter {
       },
     );
 
+    const configFileName = options.generateTypeScriptConfig ?? 'tsconfig.json';
+
     this.configPath = path.join(
       this.options.projectInfo.projectRoot,
-      'tsconfig.json',
+      configFileName,
     );
 
     this.projectReferences =

packages/jsii/test/compiler.test.ts

@@ -1,11 +1,45 @@
-import { mkdtemp, remove, writeFile, readFile } from 'fs-extra';
+import { mkdtemp, remove, writeFile, readFile, readJson } from 'fs-extra';
 import { tmpdir } from 'os';
 import { join } from 'path';
 
 import { Compiler } from '../lib/compiler';
 import { ProjectInfo } from '../lib/project-info';
 
 describe(Compiler, () => {
+  describe('generated tsconfig', () => {
+    test('default is tsconfig.json', async () => {
+      const sourceDir = await mkdtemp(
+        join(tmpdir(), 'jsii-compiler-watch-mode-'),
+      );
+
+      const compiler = new Compiler({
+        projectInfo: _makeProjectInfo(sourceDir, 'index.d.ts'),
+      });
+
+      await compiler.emit();
+
+      expect(await readJson(join(sourceDir, 'tsconfig.json'), 'utf-8')).toEqual(
+        expectedTypeScriptConfig(),
+      );
+    });
+
+    test('file name can be customized', async () => {
+      const sourceDir = await mkdtemp(
+        join(tmpdir(), 'jsii-compiler-watch-mode-'),
+      );
+
+      const compiler = new Compiler({
+        projectInfo: _makeProjectInfo(sourceDir, 'index.d.ts'),
+        generateTypeScriptConfig: 'tsconfig.jsii.json',
+      });
+
+      await compiler.emit();
+
+      expect(
+        await readJson(join(sourceDir, 'tsconfig.jsii.json'), 'utf-8'),
+      ).toEqual(expectedTypeScriptConfig());
+    });
+  });
   test('"watch" mode', async () => {
     // This can be a little slow, allowing 15 seconds maximum here (default is 5 seconds)
     jest.setTimeout(15_000);
@@ -91,3 +125,39 @@ function _makeProjectInfo(sourceDir: string, types: string): ProjectInfo {
     excludeTypescript: [],
   };
 }
+
+function expectedTypeScriptConfig() {
+  return {
+    _generated_by_jsii_:
+      'Generated by jsii - safe to delete, and ideally should be in .gitignore',
+    compilerOptions: {
+      alwaysStrict: true,
+      charset: 'utf8',
+      composite: false,
+      declaration: true,
+      experimentalDecorators: true,
+      incremental: true,
+      inlineSourceMap: true,
+      inlineSources: true,
+      lib: ['es2019'],
+      module: 'CommonJS',
+      newLine: 'lf',
+      noEmitOnError: true,
+      noFallthroughCasesInSwitch: true,
+      noImplicitAny: true,
+      noImplicitReturns: true,
+      noImplicitThis: true,
+      noUnusedLocals: true,
+      noUnusedParameters: true,
+      resolveJsonModule: true,
+      strict: true,
+      strictNullChecks: true,
+      strictPropertyInitialization: true,
+      stripInternal: false,
+      target: 'ES2019',
+      tsBuildInfoFile: 'tsconfig.tsbuildinfo',
+    },
+    exclude: ['node_modules'],
+    include: [join('**', '*.ts')],
+  };
+}