typescript-eslint · aprilrd · Apr 6, 2019 · Apr 6, 2019 · Apr 6, 2019 · Apr 7, 2019
diff --git a/packages/eslint-plugin/README.md b/packages/eslint-plugin/README.md
@@ -151,6 +151,7 @@ Then you should add `airbnb` (or `airbnb-base`) to your `extends` section of `.e
 | [`@typescript-eslint/prefer-namespace-keyword`](./docs/rules/prefer-namespace-keyword.md)                 | Require the use of the `namespace` keyword instead of the `module` keyword to declare custom TypeScript modules. (`no-internal-module` from TSLint) | :heavy_check_mark: | :wrench: |                   |
 | [`@typescript-eslint/promise-function-async`](./docs/rules/promise-function-async.md)                     | Requires any function or method that returns a Promise to be marked async. (`promise-function-async` from TSLint)                                   |                    |          | :thought_balloon: |
 | [`@typescript-eslint/restrict-plus-operands`](./docs/rules/restrict-plus-operands.md)                     | When adding two variables, operands must both be of type number or of type string. (`restrict-plus-operands` from TSLint)                           |                    |          | :thought_balloon: |
+| [`@typescript-eslint/semi`](./docs/rules/semi.md)                                                         | Require or disallow semicolons instead of ASI (semi). (`semi` from TSLint)                                                               |                    | :wrench: |                   |
 | [`@typescript-eslint/type-annotation-spacing`](./docs/rules/type-annotation-spacing.md)                   | Require consistent spacing around type annotations (`typedef-whitespace` from TSLint)                                                               | :heavy_check_mark: | :wrench: |                   |
 | [`@typescript-eslint/unbound-method`](./docs/rules/unbound-method.md)                                     | Enforces unbound methods are called with their expected scope. (`no-unbound-method` from TSLint)                                                    | :heavy_check_mark: |          | :thought_balloon: |
 | [`@typescript-eslint/unified-signatures`](./docs/rules/unified-signatures.md)                             | Warns for any two overloads that could be unified into one. (`unified-signatures` from TSLint)                                                      |                    |          |                   |

diff --git a/packages/eslint-plugin/ROADMAP.md b/packages/eslint-plugin/ROADMAP.md
@@ -177,7 +177,7 @@
 | [`prefer-while`]                    | 🛑  | N/A                                                                                 |
 | [`quotemark`]                       | 🌟  | [`quotes`][quotes]                                                                  |
 | [`return-undefined`]                | 🛑  | N/A                                                                                 |
-| [`semicolon`]                       | 🌟  | [`semi`][semi]                                                                      |
+| [`semicolon`]                       | 🌓  | [`@typescript-eslint/semi`]                                                         |
 | [`space-before-function-paren`]     | 🌟  | [`space-before-function-paren`][space-after-function-paren]                         |
 | [`space-within-parens`]             | 🌟  | [`space-in-parens`][space-in-parens]                                                |
 | [`switch-final-break`]              | 🛑  | N/A                                                                                 |
@@ -611,6 +611,7 @@ Relevant plugins: [`chai-expect-keywords`](https://github.com/gavinaiken/eslint-
 [`@typescript-eslint/prefer-function-type`]: https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/prefer-function-type.md
 [`@typescript-eslint/no-for-in-array`]: https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/no-for-in-array.md
 [`@typescript-eslint/no-unnecessary-qualifier`]: https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/no-unnecessary-qualifier.md
+[`@typescript-eslint/semi`]: https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/eslint-plugin/docs/rules/semi.md
 
 <!-- eslint-plugin-import -->
 

diff --git a/packages/eslint-plugin/docs/rules/semi.md b/packages/eslint-plugin/docs/rules/semi.md
@@ -0,0 +1,74 @@
+# require or disallow semicolons instead of ASI (semi)
+
+This rule enforces consistent use of semicolons.
+
+## Rule Details
+
+This rule extends the base [eslint/semi](https://eslint.org/docs/rules/semi) rule.
+It supports all options and features of the base rule plus TS type assertions.
+
+## How to use
+
+```cjson
+{
+    // note you must disable the base rule as it can report incorrect errors
+    "semi": "off",
+    "@typescript-eslint/semi": ["error"]
+}
+```
+
+## Options
+
+See [eslint/semi options](https://eslint.org/docs/rules/semi#options).
+
+### always
+
+Examples of **incorrect** TS code for this rule with the default `"always"` option:
+
+<!-- prettier-ignore -->
+```ts
+/*eslint @typescript-eslint/semi: "error"*/
+type Foo = {}
+
+class PanCamera extends FreeCamera {
+  public invertY: boolean = false
+}
+```
+
+Examples of **correct** TS code for this rule with the default `"always"` option:
+
+<!-- prettier-ignore -->
+```ts
+/*eslint @typescript-eslint/semi: "error"*/
+type Foo = {};
+
+class PanCamera extends FreeCamera {
+  public invertY: boolean = false;
+}
+```
+
+### never
+
+Examples of **incorrect** TS code for this rule with the `"never"` option:
+
+<!-- prettier-ignore -->
+```ts
+/*eslint @typescript-eslint/semi: ["error", "never"]*/
+type Foo = {};
+
+class PanCamera extends FreeCamera {
+  public invertY: boolean = false;
+}
+```
+
+Examples of **correct** TS code for this rule with the `"never"` option:
+
+<!-- prettier-ignore -->
+```ts
+/*eslint @typescript-eslint/semi: ["error", "never"]*/
+type Foo = {}
+
+class PanCamera extends FreeCamera {
+  public invertY: boolean = false
+}
+```
diff --git a/packages/eslint-plugin/src/rules/semi.ts b/packages/eslint-plugin/src/rules/semi.ts
@@ -0,0 +1,64 @@
+import { TSESTree, AST_NODE_TYPES } from '@typescript-eslint/typescript-estree';
+import baseRule from 'eslint/lib/rules/semi';
+import * as util from '../util';
+
+type Options = util.InferOptionsTypeFromRule<typeof baseRule>;
+type MessageIds = util.InferMessageIdsTypeFromRule<typeof baseRule>;
+
+export default util.createRule<Options, MessageIds>({
+  name: 'semi',
+  meta: {
+    type: 'layout',
+    docs: {
+      description: 'Require or disallow semicolons instead of ASI',
+      tslintRuleName: 'semi',
+      category: 'Stylistic Issues',
+      recommended: 'error',
+    },
+    fixable: 'code',
+    schema: baseRule.meta.schema,
+    messages: baseRule.meta.messages,
+  },
+  defaultOptions: ['always', { omitLastInOneLineBlock: false }] as Options,
+  create(context, optionsWithDefaults) {
+    // because we extend the base rule, have to update opts on the context
+    // the context defines options as readonly though...
+    const contextWithDefaults: typeof context = Object.create(context, {
+      options: {
+        writable: false,
+        configurable: false,
+        value: optionsWithDefaults,
+      },
+    });
+
+    const rules = baseRule.create(contextWithDefaults);
+
+    return Object.assign({}, rules, {
+      TSTypeAliasDeclaration(node: TSESTree.TSTypeAliasDeclaration) {
+        return rules.VariableDeclaration({
+          ...node,
+          type: AST_NODE_TYPES.VariableDeclaration,
+          kind: 'const' as 'const',
+          declarations: [],
+        });
+      },
+      ClassProperty(node: TSESTree.ClassProperty) {
+        return rules.VariableDeclaration({
+          ...node,
+          type: AST_NODE_TYPES.VariableDeclaration,
+          kind: 'const' as 'const',
+          declarations: [],
+        });
+      },
+      ExportDefaultDeclaration(node: TSESTree.ExportDefaultDeclaration) {
+        if (
+          !/(?:Class|Function|TSInterface)Declaration/.test(
+            node.declaration.type,
+          )
+        ) {
+          rules.ExportDefaultDeclaration(node);
+        }
+      },
+    });
+  },
+});