feat(eslint-plugin): update docs and fix nits

typescript-eslint · Apr 3, 2019 · aca6d08 · aca6d08
1 parent f39cc85
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diff --git a/packages/eslint-plugin/docs/rules/no-magic-numbers.md b/packages/eslint-plugin/docs/rules/no-magic-numbers.md
@@ -1,58 +1,15 @@
-# Disallow Magic Numbers (no-magic-numbers)
+# Disallow Magic Numbers (@typescript-eslint/no-magic-numbers)
 
-'Magic numbers' are numbers that occur multiple time in code without an explicit meaning.
+'Magic numbers' are numbers that occur multiple times in code without an explicit meaning.
 They should preferably be replaced by named constants.
 
-```js
-var now = Date.now(),
-  inOneHour = now + 60 * 60 * 1000;
-```
-
 ## Rule Details
 
-The `no-magic-numbers` rule aims to make code more readable and refactoring easier by ensuring that special numbers
-are declared as constants to make their meaning explicit.
-
-**_This rule was taken from the ESLint core rule `no-magic-numbers`._**
-**_Available options and test cases may vary depending on the version of ESLint installed in the system._**
-
-Examples of **incorrect** code for this rule:
-
-```js
-/*eslint no-magic-numbers: "error"*/
-
-var dutyFreePrice = 100,
-  finalPrice = dutyFreePrice + dutyFreePrice * 0.25;
-```
+The `@typescript-eslint/no-magic-numbers` rule extends the `no-magic-numbers` rule from ESLint core, and adds support for handling Typescript specific code that would otherwise trigger the rule.
 
-```js
-/*eslint no-magic-numbers: "error"*/
+See the [ESLint documentation](https://eslint.org/docs/rules/no-magic-numbers) for more details on the `no-magic-numbers` rule.
 
-var data = ['foo', 'bar', 'baz'];
-
-var dataLast = data[2];
-```
-
-```js
-/*eslint no-magic-numbers: "error"*/
-
-var SECONDS;
-
-SECONDS = 60;
-```
-
-Examples of **correct** code for this rule:
-
-```js
-/*eslint no-magic-numbers: "error"*/
-
-var TAX = 0.25;
-
-var dutyFreePrice = 100,
-  finalPrice = dutyFreePrice + dutyFreePrice * TAX;
-```
-
-## Options
+## Rule Changes
 
 ```cjson
 {
@@ -62,79 +19,7 @@ var dutyFreePrice = 100,
 }
 ```
 
-### ignore
-
-An array of numbers to ignore. It's set to `[]` by default.
-If provided, it must be an `Array`.
-
-Examples of **correct** code for the sample `{ "ignore": [1] }` option:
-
-```js
-/*eslint no-magic-numbers: ["error", { "ignore": [1] }]*/
-
-var data = ['foo', 'bar', 'baz'];
-var dataLast = data.length && data[data.length - 1];
-```
-
-### ignoreArrayIndexes
-
-A boolean to specify if numbers used as array indexes are considered okay. `false` by default.
-
-Examples of **correct** code for the `{ "ignoreArrayIndexes": true }` option:
-
-```js
-/*eslint no-magic-numbers: ["error", { "ignoreArrayIndexes": true }]*/
-
-var data = ['foo', 'bar', 'baz'];
-var dataLast = data[2];
-```
-
-### enforceConst
-
-A boolean to specify if we should check for the const keyword in variable declaration of numbers. `false` by default.
-
-Examples of **incorrect** code for the `{ "enforceConst": true }` option:
-
-```js
-/*eslint no-magic-numbers: ["error", { "enforceConst": true }]*/
-
-var TAX = 0.25;
-
-var dutyFreePrice = 100,
-  finalPrice = dutyFreePrice + dutyFreePrice * TAX;
-```
-
-### detectObjects
-
-A boolean to specify if we should detect numbers when setting object properties for example. `false` by default.
-
-Examples of **incorrect** code for the `{ "detectObjects": true }` option:
-
-```js
-/*eslint no-magic-numbers: ["error", { "detectObjects": true }]*/
-
-var magic = {
-  tax: 0.25,
-};
-
-var dutyFreePrice = 100,
-  finalPrice = dutyFreePrice + dutyFreePrice * magic.tax;
-```
-
-Examples of **correct** code for the `{ "detectObjects": true }` option:
-
-```js
-/*eslint no-magic-numbers: ["error", { "detectObjects": true }]*/
-
-var TAX = 0.25;
-
-var magic = {
-  tax: TAX,
-};
-
-var dutyFreePrice = 100,
-  finalPrice = dutyFreePrice + dutyFreePrice * magic.tax;
-```
+In addition to the options supported by the `no-magic-numbers` rule in ESLint core, the rule adds the following options:
 
 ### ignoreNumericLiteralTypes
 
@@ -143,15 +28,15 @@ A boolean to specify if numbers used in Typescript numeric literal types are con
 Examples of **incorrect** code for the `{ "ignoreNumericLiteralTypes": false }` option:
 
 ```ts
-/*eslint no-magic-numbers: ["error", { "ignoreNumericLiteralTypes": false }]*/
+/*eslint @typescript-eslint/no-magic-numbers: ["error", { "ignoreNumericLiteralTypes": false }]*/
 
 type SmallPrimes = 2 | 3 | 5 | 7 | 11;
 ```
 
 Examples of **correct** code for the `{ "ignoreNumericLiteralTypes": true }` option:
 
 ```ts
-/*eslint no-magic-numbers: ["error", { "ignoreNumericLiteralTypes": true }]*/
+/*eslint @typescript-eslint/no-magic-numbers: ["error", { "ignoreNumericLiteralTypes": true }]*/
 
 type SmallPrimes = 2 | 3 | 5 | 7 | 11;
 ```

diff --git a/packages/eslint-plugin/src/rules/no-magic-numbers.ts b/packages/eslint-plugin/src/rules/no-magic-numbers.ts
@@ -11,15 +11,13 @@ import { JSONSchema4 } from 'json-schema';
 type Options = util.InferOptionsTypeFromRule<typeof baseRule>;
 type MessageIds = util.InferMessageIdsTypeFromRule<typeof baseRule>;
 
-// Original schema properties from the base rule
-const { properties } = (baseRule.meta.schema as JSONSchema4[])[0];
-
 // Extend base schema with additional property to ignore TS numeric literal types
-if (properties) {
-  properties.ignoreNumericLiteralTypes = {
+const properties = {
+  ...(baseRule.meta.schema as JSONSchema4[])[0].properties,
+  ignoreNumericLiteralTypes: {
     type: 'boolean',
-  };
-}
+  },
+};
 
 export default util.createRule<Options, MessageIds>({
   name: 'no-magic-numbers',
@@ -30,7 +28,7 @@ export default util.createRule<Options, MessageIds>({
       category: 'Best Practices',
       recommended: false,
     },
-    schema: baseRule.meta.schema,
+    schema: { ...baseRule.meta.schema, ...properties },
     messages: baseRule.meta.messages,
   },
   defaultOptions: [
@@ -62,7 +60,7 @@ export default util.createRule<Options, MessageIds>({
      */
     function isGrandparentTSTypeAliasDeclaration(node: TSESTree.Node): boolean {
       return node.parent && node.parent.parent
-        ? AST_NODE_TYPES.TSTypeAliasDeclaration === node.parent.parent.type
+        ? node.parent.parent.type === AST_NODE_TYPES.TSTypeAliasDeclaration
         : false;
     }
 
@@ -76,7 +74,7 @@ export default util.createRule<Options, MessageIds>({
       if (
         node.parent &&
         node.parent.parent &&
-        AST_NODE_TYPES.TSUnionType === node.parent.parent.type
+        node.parent.parent.type === AST_NODE_TYPES.TSUnionType
       ) {
         return isGrandparentTSTypeAliasDeclaration(node.parent);
       }
@@ -92,7 +90,7 @@ export default util.createRule<Options, MessageIds>({
      */
     function isParentTSLiteralType(node: TSESTree.Node): boolean {
       return node.parent
-        ? AST_NODE_TYPES.TSLiteralType === node.parent.type
+        ? node.parent.type === AST_NODE_TYPES.TSLiteralType
         : false;
     }