Add ability to resolve "extends" directive in tsconfig.json

kulshekhar · Jan 17, 2017 · f910ca8 · f910ca8
1 parent 78c353c
commit f910ca8
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Showing 5 changed files with 59 additions and 7 deletions.
diff --git a/src/utils.ts b/src/utils.ts
@@ -73,7 +73,14 @@ export function getTSConfig(globals, collectCoverage: boolean = false) {
     config = 'tsconfig.json';
   }
   if (typeof config === 'string') {
-    config = require(path.resolve(config)).compilerOptions;
+    const configPath = path.resolve(config);
+    const external = require(configPath);
+    config = external.compilerOptions || {};
+
+    if (typeof external.extends === 'string') {
+      const parentConfigPath = path.join(path.dirname(configPath), external.extends);
+      config = Object.assign({}, require(parentConfigPath).compilerOptions, config);
+    }
   }
   config.module = config.module || tsc.ModuleKind.CommonJS;
   config.jsx = config.jsx || tsc.JsxEmit.React;
@@ -89,4 +96,4 @@ export function getTSConfig(globals, collectCoverage: boolean = false) {
   }
 
   return tsc.convertCompilerOptionsFromJson(config, undefined).options;
-}
+}
diff --git a/tests/__tests__/tsconfig-string.spec.ts b/tests/__tests__/tsconfig-string.spec.ts
@@ -52,4 +52,35 @@ describe('get ts config from string', () => {
     });
   });
 
-});
+  it('should correctly resolve the "extends" directive', () => {
+    const {getTSConfig} = require('../../src/utils');
+    const result = getTSConfig({
+      '__TS_CONFIG__': 'extends-tsconfig.json'
+    });
+
+    expect(result).toEqual ({
+      'target': 2,
+      'module': 1,
+      'moduleResolution': 2,
+      'noEmitOnError': true,
+      'jsx': 2
+    });
+  });
+
+  it('should correctly override any config in the "extends" directive', () => {
+    const {getTSConfig} = require('../../src/utils');
+    const result = getTSConfig({
+      '__TS_CONFIG__': 'extends-with-overrides-tsconfig.json'
+    });
+
+    expect(result).toEqual ({
+      'target': 1,
+      'module': 1,
+      'moduleResolution': 2,
+      'noEmitOnError': true,
+      'jsx': 2,
+      'noImplicitAny': true
+    });
+  });
+
+});
diff --git a/tests/__ts-jest-mocks__/path.ts b/tests/__ts-jest-mocks__/path.ts
@@ -3,7 +3,9 @@ import { } from 'node';
 
 interface MockedPath {
   __setBaseDir(newBaseDir);
-  resolve(args);
+  resolve(...args);
+  dirname(...args);
+  join(...args);
 }
 
 const path = require.requireActual('path');
@@ -19,11 +21,13 @@ function __setBaseDir(newBaseDir) {
 
 // A custom version of `readdirSync` that reads from the special mocked out
 // file list set via __setMockFiles
-function resolve(args) {
-  return path.resolve(baseDir, args);
+function resolve(...args) {
+  return path.resolve(baseDir, ...args);
 }
 
 mockedPath.__setBaseDir = __setBaseDir;
 mockedPath.resolve = resolve;
+mockedPath.dirname = path.dirname;
+mockedPath.join = path.join;
 
-module.exports = mockedPath;
+module.exports = mockedPath;
diff --git a/tests/tsconfig-test/extends-tsconfig.json b/tests/tsconfig-test/extends-tsconfig.json
@@ -0,0 +1,3 @@
+{
+  "extends": "./my-tsconfig.json"
+}
diff --git a/tests/tsconfig-test/extends-with-overrides-tsconfig.json b/tests/tsconfig-test/extends-with-overrides-tsconfig.json
@@ -0,0 +1,7 @@
+{
+  "extends": "./my-tsconfig.json",
+  "compilerOptions": {
+    "target": "ES5",
+    "noImplicitAny": true
+  }
+}