refactor(ivy): run the compiler compliance tests against ngtsc (#24862)

This commit moves the compiler compliance tests into compiler-cli,
and uses ngtsc to run them instead of the custom compilation
pipeline used before. Testing against ngtsc allows for validation
of the real compiler output.

This commit also fixes a few small issues that prevented the tests
from passing.

PR Close #24862

packages/compiler-cli/test/compliance/mock_compiler_spec.ts

@@ -0,0 +1,217 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+
+import {MockDirectory, setup} from '@angular/compiler/test/aot/test_util';
+import {compile, expectEmit} from './mock_compile';
+
+describe('mock_compiler', () => {
+  // This produces a MockDirectory of the file needed to compile an Angular application.
+  // This setup is performed in a beforeAll which populates the map returned.
+  const angularFiles = setup({
+    compileAngular: true,
+    compileAnimations: false,
+    compileCommon: true,
+  });
+
+  describe('compiling', () => {
+    // To use compile you need to supply the files in a MockDirectory that can be merged
+    // with a set of "environment" files such as the angular files.
+    it('should be able to compile a simple application', () => {
+      const files = {
+        app: {
+          'hello.component.ts': `
+            import {Component, Input} from '@angular/core';
+
+            @Component({template: 'Hello {{name}}!'})
+            export class HelloComponent {
+              @Input() name: string = 'world';
+            }
+          `,
+          'hello.module.ts': `
+            import {NgModule} from '@angular/core';
+            import {HelloComponent} from './hello.component';
+
+            @NgModule({declarations: [HelloComponent]})
+            export class HelloModule {}
+          `
+        }
+      };
+      const result = compile(files, angularFiles);
+
+      // result.source contains just the emitted factory declarations regardless of the original
+      // module.
+      expect(result.source).toContain('Hello');
+    });
+  });
+
+  describe('expecting emitted output', () => {
+    it('should be able to find a simple expression in the output', () => {
+      const files = {
+        app: {
+          'hello.component.ts': `
+            import {Component, Input} from '@angular/core';
+
+            @Component({template: 'Hello {{name}}! Your name as {{name.length}} characters'})
+            export class HelloComponent {
+              @Input() name: string = 'world';
+            }
+          `,
+          'hello.module.ts': `
+            import {NgModule} from '@angular/core';
+            import {HelloComponent} from './hello.component';
+
+            @NgModule({declarations: [HelloComponent]})
+            export class HelloModule {}
+          `
+        }
+      };
+
+      const result = compile(files, angularFiles);
+
+      // The expression can expected directly.
+      expectEmit(result.source, 'name.length', 'name length expression not found');
+
+      // Whitespace is not significant
+      expectEmit(
+          result.source, 'name   \n\n   .  \n    length',
+          'name length expression not found (whitespace)');
+    });
+  });
+
+  it('should be able to skip untested regions (… and // ...)', () => {
+    const files = {
+      app: {
+        'hello.component.ts': `
+          import {Component, Input} from '@angular/core';
+
+          @Component({template: 'Hello {{name}}! Your name as {{name.length}} characters'})
+          export class HelloComponent {
+            @Input() name: string = 'world';
+          }
+        `,
+        'hello.module.ts': `
+          import {NgModule} from '@angular/core';
+          import {HelloComponent} from './hello.component';
+
+          @NgModule({declarations: [HelloComponent]})
+          export class HelloModule {}
+        `
+      }
+    };
+
+    const result = compile(files, angularFiles);
+
+    // The special character … means anything can be generated between the two sections allowing
+    // skipping sections of the output that are not under test. The ellipsis unicode char (…) is
+    // used instead of '...' because '...' is legal JavaScript (the spread operator) and might
+    // need to be tested. `// ...` could also be used in place of `…`.
+    expectEmit(result.source, 'ctx.name … ctx.name.length', 'could not find correct length access');
+    expectEmit(
+        result.source, 'ctx.name // ... ctx.name.length', 'could not find correct length access');
+  });
+
+  it('should be able to skip TODO comments (// TODO)', () => {
+    const files = {
+      app: {
+        'hello.component.ts': `
+          import {Component, Input} from '@angular/core';
+
+          @Component({template: 'Hello!'})
+          export class HelloComponent { }
+        `,
+        'hello.module.ts': `
+          import {NgModule} from '@angular/core';
+          import {HelloComponent} from './hello.component';
+
+          @NgModule({declarations: [HelloComponent]})
+          export class HelloModule {}
+        `
+      }
+    };
+
+    const result = compile(files, angularFiles);
+
+    expectEmit(
+        result.source, `
+    // TODO: this comment should not be taken into account
+    $r3$.ɵT(0, "Hello!");
+    // TODO: this comment should not be taken into account
+    `,
+        'todo comments should be ignored');
+  });
+
+
+  it('should be able to enforce consistent identifiers', () => {
+    const files = {
+      app: {
+        'hello.component.ts': `
+          import {Component, Input} from '@angular/core';
+
+          @Component({template: 'Hello {{name}}! Your name as {{name.length}} characters'})
+          export class HelloComponent {
+            @Input() name: string = 'world';
+          }
+        `,
+        'hello.module.ts': `
+          import {NgModule} from '@angular/core';
+          import {HelloComponent} from './hello.component';
+
+          @NgModule({declarations: [HelloComponent]})
+          export class HelloModule {}
+        `
+      }
+    };
+
+    const result = compile(files, angularFiles);
+
+    // IDENT can be used a wild card for any identifier
+    expectEmit(result.source, 'IDENT.name', 'could not find context access');
+
+    // $<ident>$ can be used as a wild-card but all the content matched by the identifiers must
+    // match each other.
+    // This is useful if the code generator is free to invent a name but should use the name
+    // consistently.
+    expectEmit(
+        result.source, '$ctx$.$name$ … $ctx$.$name$.length',
+        'could not find correct length access');
+  });
+
+  it('should be able to enforce that identifiers match a regexp', () => {
+    const files = {
+      app: {
+        'hello.component.ts': `
+          import {Component, Input} from '@angular/core';
+
+          @Component({template: 'Hello {{name}}! Your name as {{name.length}} characters'})
+          export class HelloComponent {
+            @Input() name: string = 'world';
+          }
+        `,
+        'hello.module.ts': `
+          import {NgModule} from '@angular/core';
+          import {HelloComponent} from './hello.component';
+
+          @NgModule({declarations: [HelloComponent]})
+          export class HelloModule {}
+        `
+      }
+    };
+
+    const result = compile(files, angularFiles);
+
+    // Pass: `$n$` ends with `ME` in the generated code
+    expectEmit(result.source, '$ctx$.$n$ … $ctx$.$n$.length', 'Match names', {'$n$': /ME$/i});
+
+    // Fail: `$n$` does not match `/(not)_(\1)/` in the generated code
+    expect(() => {
+      expectEmit(
+          result.source, '$ctx$.$n$ … $ctx$.$n$.length', 'Match names', {'$n$': /(not)_(\1)/});
+    }).toThrowError(/"\$n\$" is "name" which doesn't match \/\(not\)_\(\\1\)\//);
+  });
+});