Error Prevention Rules

/**
 * Avoid mistakes when naming methods defined on the scope object
 * Detects typos in scope method names that could lead to runtime errors
 */
const avoidScopeTypos = {
  meta: {
    docs: { url: "https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/rules/avoid-scope-typos.md" };
    schema: [];
  };
  create: (context: ESLintContext) => ESLintVisitor;
};

// ✗ BAD - Common typos that cause runtime errors
$scope.$on('$destory', handler); // Should be '$destroy'
$scope.$applyAsync(); // Missing function argument

// ✓ GOOD - Correct scope method usage
$scope.$on('$destroy', handler);
$scope.$applyAsync(function() { /* handler */ });

/**
 * Require using angular.module() getter syntax instead of storing in variables
 * Enforces consistent module access pattern: angular.module('myModule')
 * Linked to John Papa's Angular Style Guide y022
 */
const moduleGetter = {
  meta: {
    docs: { url: "https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/rules/module-getter.md" };
    schema: [];
  };
  create: (context: ESLintContext) => ESLintVisitor;
};

// ✗ BAD - Storing module reference in variable
var app = angular.module('myApp');
app.controller('MyController', MyController);

// ✓ GOOD - Using getter syntax consistently
angular.module('myApp').controller('MyController', MyController);

/**
 * Disallow assigning modules to variables
 * Enforces consistent module creation pattern
 * Linked to John Papa's Angular Style Guide y021
 */
const moduleSetter = {
  meta: {
    docs: { url: "https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/rules/module-setter.md" };
    schema: [];
  };
  create: (context: ESLintContext) => ESLintVisitor;
};

// ✗ BAD - Assigning module to variable
var app = angular.module('myApp', []);

// ✓ GOOD - Direct module usage
angular.module('myApp', []);

/**
 * Disallow use of internal angular properties prefixed with $$
 * Prevents reliance on Angular's private/internal APIs that may change
 */
const noPrivateCall = {
  meta: {
    docs: { url: "https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/rules/no-private-call.md" };
    schema: [];
  };
  create: (context: ESLintContext) => ESLintVisitor;
};

// ✗ BAD - Using internal Angular properties
var watchers = $scope.$$watchers;
element.$$isolateScope();

// ✓ GOOD - Using public APIs only
// Use documented public APIs instead of internal properties

/**
 * Check for common misspelling $on('destroy', ...)
 * Prevents typos in lifecycle event handling that cause memory leaks
 */
const onDestroy = {
  meta: {
    docs: { url: "https://github.com/Gillespie59/eslint-plugin-angular/blob/master/docs/rules/on-destroy.md" };
    schema: [];
  };
  create: (context: ESLintContext) => ESLintVisitor;
};

// ✗ BAD - Common misspelling causes handler to never be called
$scope.$on('destroy', function() {
  // cleanup code that never runs
});

// ✓ GOOD - Correct event name
$scope.$on('$destroy', function() {
  // cleanup code runs properly
});

interface ESLintContext {
  getSourceCode(): SourceCode;
  report(descriptor: ReportDescriptor): void;
  settings: {
    angular?: number; // Angular version (1 or 2)
  };
}

interface ESLintVisitor {
  [key: string]: (node: any) => void;
}

interface ReportDescriptor {
  node: any;
  message: string;
  data?: Record<string, any>;
}