feat!: @typescript-eslint/no-magic-numbers

Co-authored-by: Rostislav Simonik <rostislav.simonik@technologystudio.sk>

src/fixture.ts

@@ -31,10 +31,13 @@ export interface Boo {
  * https://github.com/mightyiam/eslint-config-love/issues/110
  */
 // Inline callbacks don't need return types:
+const ONE_MILLISECOND = 1
 setTimeout(() => {
   console.log()
-}, 1)
+}, ONE_MILLISECOND)
 
 // The return type is clear from the left side of the assignment:
+// eslint-disable-next-line @typescript-eslint/no-magic-numbers
 const double: (n: number) => number = (n) => n * 2
+// eslint-disable-next-line @typescript-eslint/no-magic-numbers
 ;[1, 2].map(double)

src/index.ts

@@ -15,6 +15,7 @@ const rules = {
       'ts-ignore': true,
       'ts-nocheck': true,
       'ts-check': false,
+      // eslint-disable-next-line @typescript-eslint/no-magic-numbers
       minimumDescriptionLength: 3,
     },
   ],
@@ -76,6 +77,7 @@ const rules = {
     },
   ],
   '@typescript-eslint/init-declarations': ['error', 'always'],
+  // eslint-disable-next-line @typescript-eslint/no-magic-numbers
   '@typescript-eslint/max-params': ['error', { max: 4 }],
   '@typescript-eslint/method-signature-style': ['error'],
   '@typescript-eslint/naming-convention': [
@@ -132,6 +134,21 @@ const rules = {
   ],
   '@typescript-eslint/no-invalid-void-type': ['error'],
   '@typescript-eslint/no-loop-func': ['error'],
+  '@typescript-eslint/no-magic-numbers': [
+    'error',
+    {
+      ignore: [],
+      ignoreArrayIndexes: false,
+      ignoreDefaultValues: false,
+      ignoreClassFieldInitialValues: false,
+      enforceConst: true,
+      detectObjects: true,
+      ignoreEnums: true,
+      ignoreNumericLiteralTypes: false,
+      ignoreReadonlyClassProperties: true,
+      ignoreTypeIndexes: false,
+    },
+  ],
   '@typescript-eslint/no-misused-new': ['error'],
   '@typescript-eslint/no-misused-promises': ['error'],
   '@typescript-eslint/no-namespace': ['error'],

src/test/_expected-exported-value.ts

@@ -18,6 +18,7 @@ export const expectedExportedValue: TSESLint.FlatConfig.Config = {
     promise: promisePlugin,
   },
   rules: {
+    'no-magic-numbers': ['off'],
     'no-var': ['error'],
     'object-shorthand': ['warn', 'properties'],
 
@@ -175,6 +176,7 @@ export const expectedExportedValue: TSESLint.FlatConfig.Config = {
         'ts-ignore': true,
         'ts-nocheck': true,
         'ts-check': false,
+        // eslint-disable-next-line @typescript-eslint/no-magic-numbers
         minimumDescriptionLength: 3,
       },
     ],
@@ -236,6 +238,7 @@ export const expectedExportedValue: TSESLint.FlatConfig.Config = {
       },
     ],
     '@typescript-eslint/init-declarations': ['error', 'always'],
+    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
     '@typescript-eslint/max-params': ['error', { max: 4 }],
     '@typescript-eslint/method-signature-style': ['error'],
     '@typescript-eslint/naming-convention': [
@@ -292,6 +295,21 @@ export const expectedExportedValue: TSESLint.FlatConfig.Config = {
     ],
     '@typescript-eslint/no-invalid-void-type': ['error'],
     '@typescript-eslint/no-loop-func': ['error'],
+    '@typescript-eslint/no-magic-numbers': [
+      'error',
+      {
+        ignore: [],
+        ignoreArrayIndexes: false,
+        ignoreDefaultValues: false,
+        ignoreClassFieldInitialValues: false,
+        enforceConst: true,
+        detectObjects: true,
+        ignoreEnums: true,
+        ignoreNumericLiteralTypes: false,
+        ignoreReadonlyClassProperties: true,
+        ignoreTypeIndexes: false,
+      },
+    ],
     '@typescript-eslint/no-misused-new': ['error'],
     '@typescript-eslint/no-misused-promises': ['error'],
     '@typescript-eslint/no-namespace': ['error'],

src/test/_rules_to_consider.ts

@@ -1,5 +1,4 @@
 export const rulesToConsider = [
-  '@typescript-eslint/no-magic-numbers',
   '@typescript-eslint/no-meaningless-void-operator',
   '@typescript-eslint/no-mixed-enums',
   '@typescript-eslint/no-non-null-asserted-nullish-coalescing',
@@ -151,7 +150,6 @@ export const rulesToConsider = [
   'no-invalid-this',
   'no-label-var',
   'no-lonely-if',
-  'no-magic-numbers',
   'no-multi-assign',
   'no-negated-condition',
   'no-nested-ternary',

src/test/_util.ts

@@ -42,24 +42,25 @@ export const getPkgDetails = async (): Promise<PkgDetails> => {
 
 export const isSingleCaretRange = (rangeStr: string): boolean => {
   const range = new semver.Range(rangeStr)
-  return (
-    range.set.length === 1 &&
-    range.set[0].length === 2 &&
-    range.set[0][0].operator === '>=' &&
-    range.set[0][1].operator === '<'
-  )
+  /* eslint-disable @typescript-eslint/no-magic-numbers */
+  if (range.set.length !== 1) return false
+  const comparators = range.set[0]
+  if (comparators.length !== 2) return false
+  return comparators[0].operator === '>=' && comparators[1].operator === '<'
+  /* eslint-enable @typescript-eslint/no-magic-numbers */
 }
 
 export const isPinnedRange = (rangeStr: string): boolean => {
   const range = new semver.Range(rangeStr)
-  return (
-    range.set.length === 1 &&
-    range.set[0].length === 1 &&
-    range.set[0][0].operator === ''
-  )
+  /* eslint-disable @typescript-eslint/no-magic-numbers */
+  if (range.set.length !== 1) return false
+  const comparators = range.set[0]
+  return comparators.length === 1 && comparators[0].operator === ''
+  /* eslint-enable @typescript-eslint/no-magic-numbers */
 }
 
 export const extractVersionRange = (spec: string): string =>
+  // eslint-disable-next-line @typescript-eslint/no-magic-numbers
   spec.split('@').slice(-1)[0]
 
 const ourRules_ = exported.rules

src/test/compatibility.ts

@@ -49,6 +49,7 @@ test('our configuration is compatible with the plugin and parser at bottom of de
 
   const results = await eslint.lintText('', { filePath: 'src/index.ts' })
 
+  // eslint-disable-next-line @typescript-eslint/no-magic-numbers
   t.true(results.length > 0)
   results.forEach((result) => t.deepEqual(result.messages, [], result.filePath))
 })

src/test/resolved-config.ts

@@ -44,7 +44,12 @@ test('rules', async (t) => {
       if (!Array.isArray(value)) throw new Error()
       const [level, ...options] = value
       if (typeof level === 'number') throw new Error()
-      return [name, [{ error: 2, warn: 1, off: 0 }[level], ...options]]
+      enum Level {
+        error = 2,
+        warn = 1,
+        off = 0,
+      }
+      return [name, [Level[level], ...options]]
     }),
   )
   t.deepEqual(actual.rules, normalized)

src/test/rules.ts

@@ -79,6 +79,7 @@ test('no intersection between lists', (t) => {
     }, {})
 
   const intersection = Object.fromEntries(
+    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
     Object.entries(counts).filter(([_rule, inLists]) => inLists.length > 1),
   )
 
@@ -115,6 +116,7 @@ test('JS equivalent rules are off', async (t) => {
 
     if (baseRuleConfig === undefined) return false
     if (!Array.isArray(baseRuleConfig)) throw new Error()
+    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
     const severity = baseRuleConfig[0]
     if (typeof severity !== 'string') throw new Error()
     return severity !== 'off'