test(compiler-cli): add tests to verify import generation in TCB files/blocks (#54983)

devversion · dylhunn · commit ed271ebb3767 · 2024-03-27T10:18:30.000-07:00
This commit adds some unit tests verifying the import generation in TCB files and inline blocks. We don't seem to have any unit tests for these in general. This commit adds some, verifying some characteristics we would like to guarantee. PR Close #54983
diff --git a/packages/compiler-cli/src/ngtsc/typecheck/test/type_check_block_spec.ts b/packages/compiler-cli/src/ngtsc/typecheck/test/type_check_block_spec.ts
@@ -8,10 +8,11 @@
 
 import ts from 'typescript';
 
+import {absoluteFrom, getSourceFileOrError} from '../../file_system';
 import {initMockFileSystem} from '../../file_system/testing';
 import {Reference} from '../../imports';
-import {TypeCheckingConfig} from '../api';
-import {ALL_ENABLED_CONFIG, tcb, TestDeclaration, TestDirective} from '../testing';
+import {OptimizeFor, TypeCheckingConfig} from '../api';
+import {ALL_ENABLED_CONFIG, setup, tcb, TestDeclaration, TestDirective} from '../testing';
 
 
 describe('type check blocks', () => {
@@ -1744,4 +1745,55 @@ describe('type check blocks', () => {
       expect(result).toContain('(this).trackingFn(_t2, _t1, ((this).prop));');
     });
   });
+
+  describe('import generation', () => {
+    const TEMPLATE = `<div dir [test]="null"></div>`;
+    const DIRECTIVE: TestDeclaration = {
+      type: 'directive',
+      name: 'Dir',
+      selector: '[dir]',
+      inputs: {
+        test: {
+          isSignal: true,
+          bindingPropertyName: 'test',
+          classPropertyName: 'test',
+          required: true,
+          transform: null,
+        }
+      }
+    };
+
+    it('should prefer namespace imports in type check files for new imports', () => {
+      const result = tcb(TEMPLATE, [DIRECTIVE]);
+
+      expect(result).toContain(`import * as i1 from '@angular/core';`);
+      expect(result).toContain(`[i1.ɵINPUT_SIGNAL_BRAND_WRITE_TYPE]`);
+    });
+
+    it('should re-use existing imports from original source files', () => {
+      // This is especially important for inline type check blocks.
+      // See: https://github.com/angular/angular/pull/53521#pullrequestreview-1778130879.
+      const {templateTypeChecker, program, programStrategy} = setup([{
+        fileName: absoluteFrom('/test.ts'),
+        templates: {'AppComponent': TEMPLATE},
+        declarations: [DIRECTIVE],
+        source: `
+          import {Component} from '@angular/core'; // should be re-used
+
+          class AppComponent {}
+          export class Dir {}
+        `,
+      }]);
+
+      // Trigger type check block generation.
+      templateTypeChecker.getDiagnosticsForFile(
+          getSourceFileOrError(program, absoluteFrom('/test.ts')), OptimizeFor.SingleFile);
+
+      const testSf = getSourceFileOrError(programStrategy.getProgram(), absoluteFrom('/test.ts'));
+      expect(testSf.text)
+          .toContain(
+              `import { Component, ɵINPUT_SIGNAL_BRAND_WRITE_TYPE } from '@angular/core'; // should be re-used`);
+      expect(testSf.text).toContain(`[ɵINPUT_SIGNAL_BRAND_WRITE_TYPE]`);
+    });
+  });
 });
