An unhandled exception occurred: Cannot read property 'start' of undefined on linting after migrating existing project

[KeithGillette]

Migrating an existing @angular@11.2.5 project from tslint@6.1.3 to angular-eslint@2.0.0 following the README.md instructions, I receive the following error with no reference to an offending rule or file:

An unhandled exception occurred: Cannot read property 'start' of undefined
See "/private/var/folders/t5/nv32j92n7rngpy281m6gj8n00000gn/T/ng-ZvGP5a/angular-errors.log" for further details.

generated .eslintrc.json:

{
  "root": true,
  "ignorePatterns": [
    "projects/**/*"
  ],
  "overrides": [
    {
      "files": [
        "*.ts"
      ],
      "parserOptions": {
        "project": [
          "tsconfig.json",
        ],
        "createDefaultProgram": true
      },
      "extends": [
        "plugin:@angular-eslint/ng-cli-compat",
        "plugin:@angular-eslint/ng-cli-compat--formatting-add-on",
        "plugin:@angular-eslint/template/process-inline-templates"
      ],
      "plugins": [
        "eslint-plugin-unicorn",
        "eslint-plugin-rxjs"
      ],
      "rules": {
        "@angular-eslint/component-max-inline-declarations": "error",
        "@angular-eslint/component-selector": [
          "error",
          {
            "type": "element",
            "prefix": "tt",
            "style": "kebab-case"
          }
        ],
        "@angular-eslint/directive-selector": [
          "error",
          {
            "type": "attribute",
            "prefix": "tt",
            "style": "camelCase"
          }
        ],
        "@angular-eslint/no-attribute-decorator": "error",
        "@angular-eslint/no-forward-ref": "error",
        "@angular-eslint/no-input-rename": "off",
        "@angular-eslint/no-lifecycle-call": "error",
        "@angular-eslint/no-pipe-impure": "error",
        "@angular-eslint/pipe-prefix": [
          "error",
          {
            "prefixes": [
              "tt"
            ]
          }
        ],
        "@angular-eslint/prefer-output-readonly": "error",
        "@angular-eslint/use-component-selector": "error",
        "@angular-eslint/use-injectable-provided-in": "error",
        "@typescript-eslint/array-type": [
          "error",
          {
            "default": "array"
          }
        ],
        "@typescript-eslint/consistent-type-definitions": "error",
        "@typescript-eslint/dot-notation": "off",
        "@typescript-eslint/explicit-member-accessibility": [
          "error",
          {
            "accessibility": "explicit",
            "overrides": {
              "accessors": "explicit"
            }
          }
        ],
        "@typescript-eslint/no-extraneous-class": "off",
        "@typescript-eslint/no-for-in-array": "error",
        "@typescript-eslint/no-inferrable-types": "off",
        "@typescript-eslint/no-shadow": [
          "error",
          {
            "hoist": "never"
          }
        ],
        "@typescript-eslint/no-this-alias": "error",
        "@typescript-eslint/no-unused-expressions": [
          "error",
          {
            "allowShortCircuit": true
          }
        ],
        "@typescript-eslint/quotes": [
          "error",
          "single",
          {
            "avoidEscape": true
          }
        ],
        "@typescript-eslint/require-await": "error",
        "@typescript-eslint/unbound-method": "error",
        "arrow-parens": [
          "error",
          "always"
        ],
        "brace-style": [
          "error",
          "1tbs"
        ],
        "id-blacklist": "off",
        "id-match": "off",
        "import/no-default-export": "error",
        "import/no-deprecated": "error",
        "import/no-extraneous-dependencies": "off",
        "max-len": [
          "error",
          {
            "code": 260
          }
        ],
        "no-duplicate-case": "error",
        "no-duplicate-imports": "error",
        "no-extra-bind": "error",
        "no-irregular-whitespace": "error",
        "no-new-func": "error",
        "no-redeclare": "error",
        "no-restricted-syntax": [
          "error",
          "ForInStatement"
        ],
        "no-return-await": "error",
        "no-sequences": "error",
        "no-template-curly-in-string": "error",
        "no-underscore-dangle": "off",
        "no-useless-constructor": "error",
        "prefer-template": "error",
        "rxjs/no-async-subscribe": "error",
        "rxjs/no-create": "error",
        "rxjs/no-ignored-replay-buffer": "error",
        "rxjs/no-index": "error",
        "rxjs/no-internal": "error",
        "rxjs/no-nested-subscribe": "error",
        "rxjs/no-sharereplay": [
          "error",
          {
            "allowConfig": true
          }
        ],
        "rxjs/no-subject-unsubscribe": "error",
        "rxjs/no-unbound-methods": "error",
        "rxjs/no-unsafe-subject-next": "error",
        "rxjs/no-unsafe-takeuntil": "error",
        "space-in-parens": [
          "off",
          "never"
        ],
        "unicorn/filename-case": "error"
      }
    },
    {
      "files": [
        "*.html"
      ],
      "extends": [
        "plugin:@angular-eslint/template/recommended"
      ],
      "rules": {
        "@angular-eslint/template/conditional-complexity": "error",
        "@angular-eslint/template/cyclomatic-complexity": [
          "error",
          {
            "maxComplexity": 5
          }
        ]
      }
    }
  ]
}

The referenced angular-errors.log:

[error] TypeError: Cannot read property 'start' of undefined
    at Linter._verifyWithoutProcessors (/absolute/path/to/node_modules/eslint/lib/linter/linter.js:1191:54)
    at Linter._verifyWithConfigArray (/absolute/path/to/node_modules/eslint/lib/linter/linter.js:1273:21)
    at Linter.verify (/absolute/path/to/node_modules/eslint/lib/linter/linter.js:1228:25)
    at Linter.verifyAndFix (/absolute/path/to/node_modules/eslint/lib/linter/linter.js:1418:29)
    at verifyText (/absolute/path/to/node_modules/eslint/lib/cli-engine/cli-engine.js:239:48)
    at CLIEngine.executeOnFiles (/absolute/path/to/node_modules/eslint/lib/cli-engine/cli-engine.js:807:28)
    at ESLint.lintFiles (/absolute/path/to/node_modules/eslint/lib/eslint/eslint.js:530:23)
    at Object.lint (/absolute/path/to/node_modules/@angular-eslint/builder/dist/utils/eslint-utils.js:52:25)
    at async run (/absolute/path/to/node_modules/@angular-eslint/builder/dist/index.js:1:1322)

How can I further troubleshoot the error?

[JamesHenry]

What is the output of:

npx ng version

[KeithGillette]

Angular CLI: 11.2.3
Node: 12.21.0
OS: darwin x64

Angular: 11.2.5
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router
... service-worker
Ivy Workspace: Yes

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1102.3
@angular-devkit/build-angular   0.1102.3
@angular-devkit/core            11.2.3
@angular-devkit/schematics      11.2.3
@angular/cdk                    11.2.3
@angular/cli                    11.2.3
@schematics/angular             11.2.3
@schematics/update              0.1102.3
rxjs                            6.6.6
typescript                      4.1.5

[richpauly13]

I was having the same error. The issue is with "@angular-eslint/template/conditional-complexity": "error". If you comment out that line ng lint works as expected.

[KeithGillette]

Thanks, @richpauly13! The @angular-eslint/template/conditional-complexity rule does indeed seem to be the source of the error. I see that the migration schematic created both a top-level .eslintrc.json and a project-level .eslint.json that extended that root level configuration, so I had to remove it from both. After doing so, the project in question completed linting successfully, though now I appear to have a lot of rule and/or or code cleanup…

[JamesHenry]

@KeithGillette please can you share the root tslint and project tslint configs you had prior to converting?

[KeithGillette]

We used only a root tslint.json for all projects:

{
	"extends": "rxjs-tslint-rules",
	"rulesDirectory": [
		"node_modules/codelyzer"
	],
	"rules": {
		"align": [
			true,
			"statements"
		],
		"array-type": [
			true,
			"array"
		],
		"arrow-parens": true,
		"ban-comma-operator": true,
		"callable-types": true,
		"class-name": true,
		"comment-format": [
			true,
			"check-space"
		],
		"curly": true,
		"deprecation": true,
		"eofline": true,
		"file-name-casing": [
			true,
			"kebab-case"
		],
		"forin": true,
		"import-blacklist": [
			true,
			"lodash",
			"primeng/primeng"
		],
		"import-spacing": true,
		"indent": [
			true,
			"tabs"
		],
		"interface-name": [
			true,
			"always-prefix"
		],
		"interface-over-type-literal": true,
		"invalid-void": true,
		"jsdoc-format": true,
		"label-position": true,
		"max-line-length": [
			true,
			260
		],
		"member-access": [
			true,
			"check-accessor"
		],
		"no-angle-bracket-type-assertion": true,
		"no-arg": true,
		"no-async-without-await": true,
		"no-bitwise": true,
		"no-console": true,
		"no-construct": true,
		"no-debugger": true,
		"no-duplicate-imports": true,
		"no-duplicate-variable": true,
		"no-duplicate-switch-case": true,
		"no-duplicate-super": true,
		"no-dynamic-delete": true,
		"no-eval": true,
		"no-for-in": true,
		"no-for-in-array": true,
		"no-inferred-empty-object-type": true,
		"no-inferrable-types": false,
		"no-internal-module": true,
		"no-irregular-whitespace": true,
		"no-implicit-dependencies": false,
		"no-invalid-template-strings": true,
		"no-misused-new": true,
		"no-object-literal-type-assertion": true,
		"no-promise-as-boolean": true,
		"no-redundant-jsdoc": true,
		"no-unnecessary-class": [
			"allow-empty-class",
			"allow-constructor-only"
		],
		"no-return-await": true,
		"no-shadowed-variable": [
			true,
			{
				"temporalDeadZone": false
			}
		],
		"no-string-literal": false,
		"no-string-throw": true,
		"no-switch-case-fall-through": true,
		"no-tautology-expression": true,
		"no-this-assignment": true,
		"no-trailing-whitespace": true,
		"no-unbound-method": [
			true,
			"ignore-static"
		],
		"no-unnecessary-callback-wrapper": true,
		"no-unsafe-finally": true,
		"no-unused-expression": [
			true,
			"allow-fast-null-checks"
		],
		"no-var-keyword": true,
		"number-literal-format": true,
		"object-literal-sort-keys": false,
		"one-line": [
			true,
			"check-open-brace",
			"check-catch",
			"check-else",
			"check-whitespace"
		],
		"prefer-conditional-expression": true,
		"prefer-const": true,
		"prefer-switch": true,
		"prefer-template": true,
		"prefer-while": true,
		"quotemark": [
			true,
			"single",
			"avoid-escape"
		],
		"radix": true,
		"rxjs-no-async-subscribe": true,
		"rxjs-no-compat": true,
		"rxjs-no-create": true,
		"rxjs-no-exposed-subjects": true,
		"rxjs-no-finnish": true,
		"rxjs-no-ignored-replay-buffer": true,
		"rxjs-no-index": true,
		"rxjs-no-internal": true,
		"rxjs-no-nested-subscribe": true,
		"rxjs-no-sharereplay": {
			"options": [
				{
					"allowConfig": true
				}
			],
			"severity": "error"
		},
		"rxjs-no-subject-unsubscribe": true,
		"rxjs-no-unbound-methods": true,
		"rxjs-no-unsafe-catch": true,
		"rxjs-no-unsafe-first": true,
		"rxjs-no-unsafe-subject-next": true,
		"rxjs-no-unsafe-switchmap": true,
		"rxjs-no-unsafe-takeuntil": true,
		"semicolon": [
			true,
			"always"
		],
		"space-within-parens": false,
		"static-this": true,
		"strict-string-expressions": true,
		"switch-final-break": [
			true,
			"always"
		],
		"triple-equals": [
			true,
			"allow-null-check"
		],
		"typedef": [
			true,
			"call-signature",
			"parameter",
			"arrow-parameter",
			"property-declaration",
			"object-destructuring",
			"array-destructuring"
		],
		"typedef-whitespace": [
			true,
			{
				"call-signature": "nospace",
				"index-signature": "nospace",
				"parameter": "nospace",
				"property-declaration": "nospace",
				"variable-declaration": "nospace"
			}
		],
		"type-literal-delimiter": true,
		"unnecessary-bind": true,
		"unnecessary-constructor": true,
		"unified-signatures": true,
		"variable-name": false,
		"whitespace": [
			true,
			"check-branch",
			"check-decl",
			"check-operator",
			"check-module",
			"check-separator",
			"check-rest-spread",
			"check-type",
			"check-typecast",
			"check-type-operator",
			"check-preblock"
		],
		// Codelyzer rules for Angular: http://codelyzer.com/rules/
		"directive-selector": [
			true,
			"attribute",
			"tt",
			"camelCase"
		],
		"component-selector": [
			true,
			"element",
			"tt",
			"kebab-case"
		],
		"component-class-suffix": true,
		"component-max-inline-declarations": true,
		"directive-class-suffix": true,
		"function-constructor": true,
		"no-attribute-decorator": true,
		"no-conflicting-lifecycle": true,
		"no-default-export": true,
		"no-forward-ref": true,
		"no-input-rename": false,
		"no-lifecycle-call": true,
		"no-host-metadata-property": true,
		"no-inputs-metadata-property": true,
		"no-output-native": true,
		"no-output-on-prefix": true,
		"no-output-rename": true,
		"no-unused-css": true,
		"no-outputs-metadata-property": true,
		"no-pipe-impure": true,
		"prefer-output-readonly": true,
		"pipe-prefix": [
			true,
			"tt"
		],
		"template-banana-in-box": true,
		"template-cyclomatic-complexity": [
			true,
			5
		],
		"template-conditional-complexity": [
			true,
			4
		],
		"use-component-selector": true,
		"use-injectable-provided-in": true,
		"use-lifecycle-interface": true,
		"use-pipe-decorator": true,
		"use-pipe-transform-interface": true
	}
}

[richpauly13]

@JamesHenry it isn't a migration script issue. I have had @angular-eslint since it was a pre-release. The error started after upgrading 1.2.0 to 2.0.0.

[JamesHenry]

Thanks for the report on this, it is resolved in 2.0.1