feat: add template-no-any rule (#755)

src/index.ts

@@ -29,6 +29,7 @@ export { Rule as PreferOutputReadonlyRule } from './preferOutputReadonlyRule';
 export { Rule as TemplateConditionalComplexityRule } from './templateConditionalComplexityRule';
 export { Rule as TemplateCyclomaticComplexityRule } from './templateCyclomaticComplexityRule';
 export { Rule as TemplateAccessibilityTabindexNoPositiveRule } from './templateAccessibilityTabindexNoPositiveRule';
+export { Rule as TemplateNoAnyRule } from './templateNoAnyRule';
 export { Rule as TemplateAccessibilityLabelForVisitor } from './templateAccessibilityLabelForRule';
 export { Rule as TemplateAccessibilityValidAriaRule } from './templateAccessibilityValidAriaRule';
 export { Rule as TemplatesAccessibilityAnchorContentRule } from './templateAccessibilityAnchorContentRule';

src/templateNoAnyRule.ts

@@ -0,0 +1,58 @@
+import { MethodCall, PropertyRead } from '@angular/compiler';
+import { IRuleMetadata, RuleFailure } from 'tslint';
+import { AbstractRule } from 'tslint/lib/rules';
+import { dedent } from 'tslint/lib/utils';
+import { SourceFile } from 'typescript';
+import { NgWalker } from './angular/ngWalker';
+import { RecursiveAngularExpressionVisitor } from './angular/templates/recursiveAngularExpressionVisitor';
+
+const ANY_TYPE_CAST_FUNCTION_NAME = '$any';
+
+export class Rule extends AbstractRule {
+  static readonly metadata: IRuleMetadata = {
+    description: `Disallows using '${ANY_TYPE_CAST_FUNCTION_NAME}' in templates.`,
+    options: null,
+    optionsDescription: 'Not configurable.',
+    rationale: dedent`
+      The use of '${ANY_TYPE_CAST_FUNCTION_NAME}' nullifies the compile-time
+      benefits of the Angular's type system.
+    `,
+    ruleName: 'template-no-any',
+    type: 'functionality',
+    typescriptOnly: true
+  };
+
+  static readonly FAILURE_STRING = `Avoid using '${ANY_TYPE_CAST_FUNCTION_NAME}' in templates`;
+
+  apply(sourceFile: SourceFile): RuleFailure[] {
+    return this.applyWithWalker(
+      new NgWalker(sourceFile, this.getOptions(), {
+        expressionVisitorCtrl: ExpressionVisitor
+      })
+    );
+  }
+}
+
+class ExpressionVisitor extends RecursiveAngularExpressionVisitor {
+  visitMethodCall(ast: MethodCall, context: any): any {
+    this.validateMethodCall(ast);
+    super.visitMethodCall(ast, context);
+  }
+
+  private generateFailure(ast: MethodCall): void {
+    const {
+      span: { end: endSpan, start: startSpan }
+    } = ast;
+
+    this.addFailureFromStartToEnd(startSpan, endSpan, Rule.FAILURE_STRING);
+  }
+
+  private validateMethodCall(ast: MethodCall): void {
+    const isAnyTypeCastFunction = ast.name === ANY_TYPE_CAST_FUNCTION_NAME;
+    const isAngularAnyTypeCastFunction = !(ast.receiver instanceof PropertyRead);
+
+    if (!isAnyTypeCastFunction || !isAngularAnyTypeCastFunction) return;
+
+    this.generateFailure(ast);
+  }
+}

test/templateNoAnyRule.spec.ts

@@ -0,0 +1,202 @@
+import { Rule } from '../src/templateNoAnyRule';
+import { assertAnnotated, assertMultipleAnnotated, assertSuccess } from './testHelper';
+
+const {
+  FAILURE_STRING,
+  metadata: { ruleName }
+} = Rule;
+
+describe(ruleName, () => {
+  describe('failure', () => {
+    it('should fail with call expression in expression binding', () => {
+      const source = `
+        @Component({
+          template: '{{ $any(framework).name }}'
+                        ~~~~~~~~~~~~~~~
+        })
+        export class Bar {}
+      `;
+      assertAnnotated({
+        message: FAILURE_STRING,
+        ruleName,
+        source
+      });
+    });
+
+    it('should fail with call expression using "this"', () => {
+      const source = `
+        @Component({
+          template: '{{ this.$any(framework).name }}'
+                        ~~~~~~~~~~~~~~~~~~~~
+        })
+        class Bar {}
+      `;
+      assertAnnotated({
+        message: FAILURE_STRING,
+        ruleName,
+        source
+      });
+    });
+
+    it('should fail with call expression in property binding', () => {
+      const source = `
+        @Component({
+          template: '<a [href]="$any(getHref())">Click here</a>'
+                                ~~~~~~~~~~~~~~~
+        })
+        class Bar {}
+      `;
+      assertAnnotated({
+        message: FAILURE_STRING,
+        ruleName,
+        source
+      });
+    });
+
+    it('should fail with call expression in an output handler', () => {
+      const source = `
+        @Component({
+          template: '<button type="button" (click)="$any(this).member = 2">Click here</button>'
+                                                    ~~~~~~~~~~
+        })
+        class Bar {}
+      `;
+      assertAnnotated({
+        message: FAILURE_STRING,
+        ruleName,
+        source
+      });
+    });
+
+    it('should fail for multiple cases', () => {
+      const source = `
+        @Component({
+          template: \`
+            {{ $any(framework).name }}
+               ~~~~~~~~~~~~~~~
+            {{ this.$any(framework).name }}
+               ^^^^^^^^^^^^^^^^^^^^
+            <a [href]="$any(getHref())">Click here</a>'
+                       ###############
+            <button type="button" (click)="$any(this).member = 2">Click here</button>
+                                           %%%%%%%%%%
+          \`
+        })
+        class Bar {}
+      `;
+      assertMultipleAnnotated({
+        failures: [
+          {
+            char: '~',
+            msg: FAILURE_STRING
+          },
+          {
+            char: '^',
+            msg: FAILURE_STRING
+          },
+          {
+            char: '#',
+            msg: FAILURE_STRING
+          },
+          {
+            char: '%',
+            msg: FAILURE_STRING
+          }
+        ],
+        ruleName,
+        source
+      });
+    });
+  });
+
+  describe('success', () => {
+    it('should pass with no call expression', () => {
+      const source = `
+        @Component({
+          template: '{{ $any }}'
+        })
+        class Bar {}
+      `;
+      assertSuccess(ruleName, source);
+    });
+
+    it('should pass for an object containing a function called "$any"', () => {
+      const source = `
+        @Component({
+          template: '{{ obj.$any() }}'
+        })
+        class Bar {
+          readonly obj = {
+            $any: () => '$any'
+          };
+        }
+      `;
+      assertSuccess(ruleName, source);
+    });
+
+    it('should pass for a nested object containing a function called "$any"', () => {
+      const source = `
+        @Component({
+          template: '{{ obj?.x?.y!.z!.$any() }}'
+        })
+        class Bar {
+          readonly obj: Partial<Xyz> = {
+            x: {
+              y: {
+                z: {
+                  $any: () => '$any'
+                }
+              }
+            }
+          };
+        }
+      `;
+      assertSuccess(ruleName, source);
+    });
+
+    it('should pass with call expression in property binding', () => {
+      const source = `
+        @Component({
+          template: '<a [href]="$test()">Click here</a>'
+        })
+        class Bar {}
+      `;
+      assertSuccess(ruleName, source);
+    });
+
+    it('should pass with call expression in an output handler', () => {
+      const source = `
+        @Component({
+          template: '<button type="button" (click)="anyClick()">Click here</button>'
+        })
+        class Bar {}
+      `;
+      assertSuccess(ruleName, source);
+    });
+
+    it('should pass for multiple cases', () => {
+      const source = `
+        @Component({
+          template: \`
+            {{ $any }}
+            {{ obj?.x?.y!.z!.$any() }}
+            <a [href]="$test()">Click here</a>
+            <button type="button" (click)="anyClick()">Click here</button>
+          \`
+        })
+        class Bar {
+          readonly obj: Partial<Xyz> = {
+            x: {
+              y: {
+                z: {
+                  $any: () => '$any'
+                }
+              }
+            }
+          };
+        }
+      `;
+      assertSuccess(ruleName, source);
+    });
+  });
+});