117616: Ported alias-imports rule

.eslintrc.json

@@ -263,6 +263,7 @@
         "rxjs/no-nested-subscribe": "off",     // todo: go over _all_ cases
 
         // Custom DSpace Angular rules
+        "dspace-angular-ts/alias-imports": "error",
         "dspace-angular-ts/themed-component-classes": "error",
         "dspace-angular-ts/themed-component-selectors": "error",
         "dspace-angular-ts/themed-component-usages": "error"

docs/lint/ts/index.md

@@ -1,6 +1,7 @@
 [DSpace ESLint plugins](../../../lint/README.md) > TypeScript rules
 _______
 
+- [`dspace-angular-ts/alias-imports`](./rules/alias-imports.md): Unclear imports should be aliased for clarity
 - [`dspace-angular-ts/themed-component-classes`](./rules/themed-component-classes.md): Formatting rules for themeable component classes
 - [`dspace-angular-ts/themed-component-selectors`](./rules/themed-component-selectors.md): Themeable component selectors should follow the DSpace convention
 - [`dspace-angular-ts/themed-component-usages`](./rules/themed-component-usages.md): Themeable components should be used via their `ThemedComponent` wrapper class

docs/lint/ts/rules/alias-imports.md

@@ -0,0 +1,58 @@
+[DSpace ESLint plugins](../../../../lint/README.md) > [TypeScript rules](../index.md) > `dspace-angular-ts/alias-imports`
+_______
+
+Unclear imports should be aliased for clarity
+
+_______
+
+[Source code](../../../../lint/src/rules/ts/alias-imports.ts)
+
+### Examples
+
+
+#### Valid code
+    
+##### correctly aliased imports
+        
+```typescript
+import { of as observableOf } from 'rxjs';
+```
+    
+
+
+
+#### Invalid code  & automatic fixes
+    
+##### imports without alias
+        
+```typescript
+import { of } from 'rxjs';
+```
+Will produce the following error(s):
+```
+This import must be aliased
+```
+        
+Result of `yarn lint --fix`:
+```typescript
+import { of as observableOf } from 'rxjs';
+```
+        
+    
+##### imports under the wrong alias
+        
+```typescript
+import { of as ofSomething } from 'rxjs';
+```
+Will produce the following error(s):
+```
+This import uses the wrong alias (should be {{ local }})
+```
+        
+Result of `yarn lint --fix`:
+```typescript
+import { of as observableOf } from 'rxjs';
+```
+        
+    
+

lint/src/rules/ts/alias-imports.ts

@@ -0,0 +1,132 @@
+import {
+  ESLintUtils,
+  TSESLint,
+  TSESTree,
+} from '@typescript-eslint/utils';
+
+import {
+  DSpaceESLintRuleInfo,
+  NamedTests,
+} from '../../util/structure';
+
+export enum Message {
+  NO_ALIAS = 'noAlias',
+  WRONG_ALIAS = 'wrongAlias',
+}
+
+export const info: DSpaceESLintRuleInfo = {
+  name: 'alias-imports',
+  meta: {
+    docs: {
+      description: 'Unclear imports should be aliased for clarity',
+    },
+    messages: {
+      [Message.NO_ALIAS]: 'This import must be aliased',
+      [Message.WRONG_ALIAS]: 'This import uses the wrong alias (should be {{ local }})',
+    },
+    fixable: 'code',
+    type: 'problem',
+    schema: [
+      {
+        type: 'array',
+        items: {
+          type: 'object',
+          properties: {
+            package: { type: 'string' },
+            imported: { type: 'string' },
+            local: { type: 'string' },
+          },
+        },
+      },
+    ],
+  },
+  defaultOptions: [
+    [
+      {
+        package: 'rxjs',
+        imported: 'of',
+        local: 'observableOf',
+      },
+    ],
+  ],
+};
+
+export const rule = ESLintUtils.RuleCreator.withoutDocs({
+  ...info,
+  create(context: TSESLint.RuleContext<Message, unknown[]>, options: any) {
+    return options[0].reduce((selectors: any, option: any) => {
+      selectors[`ImportDeclaration[source.value = "${option.package}"] > ImportSpecifier[imported.name = "${option.imported}"][local.name != "${option.local}"]`] = (node: TSESTree.ImportSpecifier) => handleUnaliasedImport(context, option, node);
+      return selectors;
+    }, {});
+  },
+});
+
+export const tests: NamedTests = {
+  plugin: info.name,
+  valid: [
+    {
+      name: 'correctly aliased imports',
+      code: `
+import { of as observableOf } from 'rxjs';
+        `,
+    },
+  ],
+  invalid: [
+    {
+      name: 'imports without alias',
+      code: `
+import { of } from 'rxjs';
+        `,
+      errors: [
+        {
+          messageId: 'noAlias',
+        },
+      ],
+      output: `
+import { of as observableOf } from 'rxjs';
+        `,
+    },
+    {
+      name: 'imports under the wrong alias',
+      code: `
+import { of as ofSomething } from 'rxjs';
+        `,
+      errors: [
+        {
+          messageId: 'wrongAlias',
+        },
+      ],
+      output: `
+import { of as observableOf } from 'rxjs';
+        `,
+    },
+  ],
+};
+
+/**
+ * Replaces the incorrectly aliased imports with the ones defined in the defaultOptions
+ *
+ * @param context The current {@link TSESLint.RuleContext}
+ * @param option The current `defaultOptions` that needs to be handled
+ * @param node The incorrect import node that should be fixed
+ */
+function handleUnaliasedImport(context: TSESLint.RuleContext<Message, unknown[]>, option: any, node: TSESTree.ImportSpecifier): void {
+  if (node.local.name === node.imported.name) {
+    context.report({
+      messageId: Message.NO_ALIAS,
+      node: node,
+      fix(fixer: TSESLint.RuleFixer) {
+        return fixer.replaceText(node.local, `${option.imported} as ${option.local}`);
+      },
+    });
+  } else {
+    context.report({
+      messageId: Message.WRONG_ALIAS,
+      data: { local: option.local },
+      node: node,
+      fix(fixer: TSESLint.RuleFixer) {
+        return fixer.replaceText(node.local, option.local);
+      },
+    });
+  }
+}

lint/src/rules/ts/index.ts

@@ -10,11 +10,13 @@ import {
   RuleExports,
 } from '../../util/structure';
 /* eslint-disable import/no-namespace */
+import * as aliasImports from './alias-imports';
 import * as themedComponentClasses from './themed-component-classes';
 import * as themedComponentSelectors from './themed-component-selectors';
 import * as themedComponentUsages from './themed-component-usages';
 
 const index = [
+  aliasImports,
   themedComponentClasses,
   themedComponentSelectors,
   themedComponentUsages,