callable-types auto fix produces invalid results

[mrweiss]

Bug Report

• TSLint version: 5.7.0
• TypeScript version: 2.5.2
• Running TSLint via: VSCode

TypeScript code being linted

export function issue(foo: any | { (param: any): any }) { foo = 'bar'; }

with tslint.json configuration:

{
  "extends": ["tslint:recommended", "tslint-react"],
  "rulesDirectory": [
    "../../../../../../../../node_modules/tslint-eslint-rules/dist/rules",
    "../../../../../../../../node_modules/tslint-microsoft-contrib",
    "../../../../../../../../node_modules/tslint-misc-rules/rules"
  ],
  "rules": {
    "quotemark": [true, "single"],
    "ter-indent": ["error", 2, { "SwitchCase": true }],
    "object-curly-spacing": ["error", "always"],
    "member-access": [false],
    "ordered-imports": [false],
    "object-literal-sort-keys": false,
    "trailing-comma": [false],
    "arrow-parens": [false],
    "object-literal-key-quotes": [false],
    "variable-name": [false],
    "no-multi-spaces": ["error", "always"],
    "no-console": [false],
    "no-bitwise": false,
    "no-empty": false,
    "no-reference": false,
    "interface-over-type-literal": false,
    "react-tsx-curly-spacing": [true, "never", { "allowMultiline": true }],
    "array-bracket-spacing": [true, "never"],
    "block-spacing": [true, "always"],
    "no-unexpected-multiline": "error",
    "curly": true,
    "jsx-alignment": true,
    "jsx-wrap-multiline": true,
    "jsx-curly-spacing": ["never"],
    "jsx-no-multiline-js": false,
    "jsx-no-lambda": false,
    "class-method-newlines": true,
    "no-consecutive-blank-lines": [true],
    "max-classes-per-file": [
      false
    ]
  }
}

Actual behavior

severity: 'Error'
message: 'Type literal has only a call signature — use `(param: any) => any` instead. (callable-types)'
at: '2,36'

on auto fix changes to:

export function issue(foo: any | (param: any) => any) { foo = 'bar'; }

which is not valid:

severity: 'Error'
message: 'missing whitespace (one-line)'
at: '2,46'
source: 'tslint'

severity: 'Error'
message: ''{' or ';' expected.'
at: '2,47'
source: 'ts'

severity: 'Error'
message: ''any' only refers to a type, but is being used as a value here.'
at: '2,50'
source: 'ts'

severity: 'Error'
message: 'unused expression, expected an assignment or function call (no-unused-expression)'
at: '2,50'
source: 'tslint'

severity: 'Error'
message: 'Missing semicolon (semicolon)'
at: '2,53'
source: 'tslint'

severity: 'Error'
message: '';' expected.'
at: '2,53'
source: 'ts'

severity: 'Error'
message: 'Cannot find name 'foo'.'
at: '2,57'
source: 'ts'

Expected behavior

Auto fixes to a valid syntax. The suggested fix by the rule definition is:

export function issue(foo: any | { (param: any) => any }) { foo = 'bar'; }

but that is not a valid TypeScript, either:

severity: 'Error'
message: '':' expected.'
at: '2,49'
source: 'ts'

[ajafff]

I can confirm that this is a bug. The fixer needs to add parens around the function signature if it is the child of a union or intersection type.

[ajafff]

Fixed by #3342