lint rule with autofix to disallow the disabled input on button elements

Author: Jens Vannerum

.eslintrc.json

@@ -293,7 +293,8 @@
       ],
       "rules": {
         // Custom DSpace Angular rules
-        "dspace-angular-html/themed-component-usages": "error"
+        "dspace-angular-html/themed-component-usages": "error",
+        "dspace-angular-html/no-disabled-attr": "error"
       }
     },
     {

lint/src/rules/html/index.ts

@@ -10,10 +10,13 @@ import {
   bundle,
   RuleExports,
 } from '../../util/structure';
+import * as noDisabledAttr from './no-disabled-attr';
 import * as themedComponentUsages from './themed-component-usages';
 
 const index = [
   themedComponentUsages,
+  noDisabledAttr,
+
 ] as unknown as RuleExports[];
 
 export = {

lint/src/rules/html/no-disabled-attr.ts

@@ -0,0 +1,144 @@
+import {
+  TmplAstBoundAttribute,
+  TmplAstTextAttribute
+} from '@angular-eslint/bundled-angular-compiler';
+import { TemplateParserServices } from '@angular-eslint/utils';
+import {
+  ESLintUtils,
+  TSESLint,
+} from '@typescript-eslint/utils';
+import {
+  DSpaceESLintRuleInfo,
+  NamedTests,
+} from '../../util/structure';
+import { getSourceCode } from '../../util/typescript';
+
+export enum Message {
+  USE_DSBTN_DISABLED = 'mustUseDsBtnDisabled',
+}
+
+export const info = {
+  name: 'no-disabled-attr',
+  meta: {
+    docs: {
+      description: `Buttons should use the \`dsBtnDisabled\` directive instead of the HTML \`disabled\` attribute for accessibility reasons.`,
+    },
+    type: 'problem',
+    fixable: 'code',
+    schema: [],
+    messages: {
+      [Message.USE_DSBTN_DISABLED]: 'Buttons should use the `dsBtnDisabled` directive instead of the `disabled` attribute.',
+    },
+  },
+  defaultOptions: [],
+} as DSpaceESLintRuleInfo;
+
+export const rule = ESLintUtils.RuleCreator.withoutDocs({
+  ...info,
+  create(context: TSESLint.RuleContext<Message, unknown[]>) {
+    const parserServices = getSourceCode(context).parserServices as TemplateParserServices;
+
+    /**
+     * Some dynamic angular inputs will have disabled as name because of how Angular handles this internally (e.g [class.disabled]="isDisabled")
+     * But these aren't actually the disabled attribute we're looking for, we can determine this by checking the details of the keySpan
+     */
+    function isOtherAttributeDisabled(node: TmplAstBoundAttribute | TmplAstTextAttribute): boolean {
+      // if the details are not null, and the details are not 'disabled', then it's not the disabled attribute we're looking for
+      return node.keySpan?.details !== null && node.keySpan?.details !== 'disabled';
+    }
+
+    /**
+     * Replace the disabled text with [dsBtnDisabled] in the template
+     */
+    function replaceDisabledText(text: string ): string {
+      const hasBrackets = text.includes('[') && text.includes(']');
+      const newDisabledText = hasBrackets ? 'dsBtnDisabled' : '[dsBtnDisabled]';
+      return text.replace('disabled', newDisabledText);
+    }
+
+    function inputIsChildOfButton(node: any): boolean {
+      return (node.parent?.tagName === 'button' || node.parent?.name === 'button');
+    }
+
+    function reportAndFix(node: TmplAstBoundAttribute | TmplAstTextAttribute) {
+      if (!inputIsChildOfButton(node) || isOtherAttributeDisabled(node)) {
+        return;
+      }
+
+      const sourceSpan = node.sourceSpan;
+      context.report({
+        messageId: Message.USE_DSBTN_DISABLED,
+        loc: parserServices.convertNodeSourceSpanToLoc(sourceSpan),
+        fix(fixer) {
+          const templateText = sourceSpan.start.file.content;
+          const disabledText = templateText.slice(sourceSpan.start.offset, sourceSpan.end.offset);
+          const newText = replaceDisabledText(disabledText);
+          return fixer.replaceTextRange([sourceSpan.start.offset, sourceSpan.end.offset], newText);
+        },
+      });
+    }
+
+    return {
+      'BoundAttribute[name="disabled"]'(node: TmplAstBoundAttribute) {
+        reportAndFix(node);
+      },
+      'TextAttribute[name="disabled"]'(node: TmplAstTextAttribute) {
+        reportAndFix(node);
+      },
+    };
+  },
+});
+
+export const tests = {
+  plugin: info.name,
+  valid: [
+    {
+      name: 'should use [dsBtnDisabled] in HTML templates',
+      code: `
+<button [dsBtnDisabled]="true">Submit</button>
+      `,
+    },
+    {
+      name: 'disabled attribute is still valid on non-button elements',
+      code: `
+<input disabled="true">
+      `,
+    },
+    {
+      name: '[disabled] attribute is still valid on non-button elements',
+      code: `
+<input [disabled]="true">
+      `,
+    },
+    {
+      name: 'angular dynamic attributes that use disabled are still valid',
+      code: `
+<button [class.disabled]="isDisabled">Submit</button>
+      `,
+    },
+  ],
+  invalid: [
+    {
+      name: 'should not use disabled attribute in HTML templates',
+      code: `
+<button disabled="true">Submit</button>
+      `,
+      errors: [{ messageId: Message.USE_DSBTN_DISABLED }],
+      output: `
+<button [dsBtnDisabled]="true">Submit</button>
+      `,
+    },
+    {
+      name: 'should not use [disabled] attribute in HTML templates',
+      code: `
+<button [disabled]="true">Submit</button>
+      `,
+      errors: [{ messageId: Message.USE_DSBTN_DISABLED }],
+      output: `
+<button [dsBtnDisabled]="true">Submit</button>
+      `,
+    },
+  ],
+} as NamedTests;
+
+export default rule;