Rule trailing-comma: TypeError: Cannot read property 'end' of undefined

[jiripospisil]

Bug Report

• TSLint version: 5.11.0
• TypeScript version: 3.0.3
• Running TSLint via: CLI or VSCode

TypeScript code being linted

class Foo {
  bar() {
    const params = {
      {}
    };

    if (true === true) {
    }
  }
}

with tslint.json configuration:

{
  "defaultSeverity": "error",
  "extends": [
    "tslint:recommended"
  ]
}

Actual behavior

tslint -c tslint.json kk.ts

The 'trailing-comma' rule threw an error in 'kk.ts':
TypeError: Cannot read property 'end' of undefined
    at cb (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/rules/trailingCommaRule.js:163:133)
    at visitNodes (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/typescript/3.0.3/node_modules/typescript/lib/typescript.js:15129:30)
    at Object.forEachChild (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/typescript/3.0.3/node_modules/typescript/lib/typescript.js:15428:21)
    at cb (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/rules/trailingCommaRule.js:170:23)
    at visitNodes (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/typescript/3.0.3/node_modules/typescript/lib/typescript.js:15129:30)
    at Object.forEachChild (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/typescript/3.0.3/node_modules/typescript/lib/typescript.js:15355:24)
    at TrailingCommaWalker.walk (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/rules/trailingCommaRule.js:172:19)
    at Rule.AbstractRule.applyWithWalker (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/language/rule/abstractRule.js:31:16)
    at Rule.apply (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/rules/trailingCommaRule.js:64:21)
    at Linter.applyRule (/private/tmp/tp-20180904190451/node_modules/.registry.npmjs.org/tslint/5.11.0/node_modules/tslint/lib/linter.js:197:29)
<snip>

Expected behavior

It should not crash.

[giladgray]

@jiripospisil to be fair, this is not valid javascript:

const params = {
    {}
};

[jiripospisil]

@jiripospisil to be fair, this is not valid javascript:

@giladgray I'm aware but it's easy to get into a state which is not valid TS/JS while in the middle of changing code.

To be clear, I'm not running TSLint manually, I'm using VSCode and it runs it automatically via vscode-tslint.

I'm fairly certain there are other ways to trigger this because I've encountered it multiple times but the provided snippet seems pretty reliable and should be enough to add some sort of a fail-safe.

[thomaspink]

Same issue, any updates on this one?

TypeError: Cannot read property 'end' of undefined
    at cb (/Users/thomas.pink/Development/angular-components/node_modules/tslint/lib/rules/trailingCommaRule.js:163:133)
    at visitNodes (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13272:30)
    at Object.forEachChild (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13421:24)
    at cb (/Users/thomas.pink/Development/angular-components/node_modules/tslint/lib/rules/trailingCommaRule.js:170:23)
    at visitNode (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13263:24)
    at Object.forEachChild (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13446:24)
    at cb (/Users/thomas.pink/Development/angular-components/node_modules/tslint/lib/rules/trailingCommaRule.js:170:23)
    at visitNode (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13263:24)
    at Object.forEachChild (/Users/thomas.pink/Development/angular-components/node_modules/typescript/lib/typescript.js:13457:24)
    at cb (/Users/thomas.pink/Development/angular-components/node_modules/tslint/lib/rules/trailingCommaRule.js:170:23)

[JoshuaKGoldberg]

Duplicate of #3808