fix(@schematics/angular): migrate TS module type to esnext

Author: clydin

packages/schematics/angular/migrations/update-8/differential-loading.ts

@@ -53,19 +53,26 @@ export function updateES5Projects(): Rule {
       return host;
     }
 
-    const scriptTarget = findPropertyInAstObject(compilerOptions, 'target');
-    if (scriptTarget && scriptTarget.value === 'es2015') {
-      return host;
-    }
-
     const recorder = host.beginUpdate(tsConfigPath);
-    if (scriptTarget) {
+
+    const scriptTarget = findPropertyInAstObject(compilerOptions, 'target');
+    if (!scriptTarget) {
+      insertPropertyInAstObjectInOrder(recorder, compilerOptions, 'target', 'es2015', 4);
+    } else if (scriptTarget.value !== 'es2015') {
       const { start, end } = scriptTarget;
       recorder.remove(start.offset, end.offset - start.offset);
       recorder.insertLeft(start.offset, '"es2015"');
-    } else {
-      insertPropertyInAstObjectInOrder(recorder, compilerOptions, 'target', 'es2015', 4);
     }
+
+    const scriptModule = findPropertyInAstObject(compilerOptions, 'module');
+    if (!scriptModule) {
+      insertPropertyInAstObjectInOrder(recorder, compilerOptions, 'module', 'esnext', 4);
+    } else if (scriptModule.value !== 'esnext') {
+      const { start, end } = scriptModule;
+      recorder.remove(start.offset, end.offset - start.offset);
+      recorder.insertLeft(start.offset, '"esnext"');
+    }
+
     host.commitUpdate(recorder);
 
     return updateBrowserlist;

packages/schematics/angular/migrations/update-8/differential-loading_spec.ts

@@ -62,6 +62,24 @@ describe('Migration to version 8', () => {
       expect(target).toBe('es2015');
     });
 
+    it(`should update 'module' to esnext when property exists`, () => {
+      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
+      const { module } = JSON.parse(tree2.readContent(tsConfigPath)).compilerOptions;
+      expect(module).toBe('esnext');
+    });
+
+    it(`should create 'module' property when doesn't exists`, () => {
+      const compilerOptions = {
+        ...oldTsConfig.compilerOptions,
+        module: undefined,
+      };
+
+      tree.overwrite(tsConfigPath, JSON.stringify({ compilerOptions }, null, 2));
+      const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
+      const { module } = JSON.parse(tree2.readContent(tsConfigPath)).compilerOptions;
+      expect(module).toBe('esnext');
+    });
+
     it(`should update browserslist file to add an non evergreen browser`, () => {
       const tree2 = schematicRunner.runSchematic('migration-07', {}, tree.branch());
       expect(tree2.readContent('/browserslist')).toContain('Chrome 41');