fix: handle ts as expression in marchers (#403)

Author: G-Rath

src/rules/__tests__/prefer-to-be-null.test.ts

@@ -43,3 +43,23 @@ ruleTester.run('prefer-to-be-null', rule, {
     },
   ],
 });
+
+new TSESLint.RuleTester({
+  parser: '@typescript-eslint/parser',
+}).run('prefer-to-be-null: typescript edition', rule, {
+  valid: [
+    "(expect('Model must be bound to an array if the multiple property is true') as any).toHaveBeenTipped()",
+  ],
+  invalid: [
+    {
+      code: 'expect(null).toBe(null as unknown as string as unknown as any);',
+      errors: [{ messageId: 'useToBeNull', column: 14, line: 1 }],
+      output: 'expect(null).toBeNull();',
+    },
+    {
+      code: 'expect("a string").not.toEqual(null as number);',
+      errors: [{ messageId: 'useToBeNull', column: 24, line: 1 }],
+      output: 'expect("a string").not.toBeNull();',
+    },
+  ],
+});

src/rules/__tests__/prefer-to-be-undefined.test.ts

@@ -41,3 +41,23 @@ ruleTester.run('prefer-to-be-undefined', rule, {
     },
   ],
 });
+
+new TSESLint.RuleTester({
+  parser: '@typescript-eslint/parser',
+}).run('prefer-to-be-undefined: typescript edition', rule, {
+  valid: [
+    "(expect('Model must be bound to an array if the multiple property is true') as any).toHaveBeenTipped()",
+  ],
+  invalid: [
+    {
+      code: 'expect(undefined).toBe(undefined as unknown as string as any);',
+      errors: [{ messageId: 'useToBeUndefined', column: 19, line: 1 }],
+      output: 'expect(undefined).toBeUndefined();',
+    },
+    {
+      code: 'expect("a string").not.toEqual(undefined as number);',
+      errors: [{ messageId: 'useToBeUndefined', column: 24, line: 1 }],
+      output: 'expect("a string").not.toBeUndefined();',
+    },
+  ],
+});

src/rules/__tests__/prefer-to-contain.test.ts

@@ -114,3 +114,19 @@ ruleTester.run('prefer-to-contain', rule, {
     },
   ],
 });
+
+new TSESLint.RuleTester({
+  parser: '@typescript-eslint/parser',
+}).run('prefer-to-be-null: typescript edition', rule, {
+  valid: [
+    "(expect('Model must be bound to an array if the multiple property is true') as any).toHaveBeenTipped()",
+    'expect(a.includes(b)).toEqual(0 as boolean);',
+  ],
+  invalid: [
+    {
+      code: 'expect(a.includes(b)).toEqual(false as boolean);',
+      errors: [{ messageId: 'useToContain', column: 23, line: 1 }],
+      output: 'expect(a).not.toContain(b);',
+    },
+  ],
+});

src/rules/prefer-to-be-null.ts

@@ -3,9 +3,11 @@ import {
   TSESTree,
 } from '@typescript-eslint/experimental-utils';
 import {
+  MaybeTypeCast,
   ParsedEqualityMatcherCall,
   ParsedExpectMatcher,
   createRule,
+  followTypeAssertionChain,
   isExpectCall,
   isParsedEqualityMatcherCall,
   parseExpectCall,
@@ -24,12 +26,13 @@ const isNullLiteral = (node: TSESTree.Node): node is NullLiteral =>
  *
  * @param {ParsedExpectMatcher} matcher
  *
- * @return {matcher is ParsedEqualityMatcherCall<NullLiteral>}
+ * @return {matcher is ParsedEqualityMatcherCall<MaybeTypeCast<NullLiteral>>}
  */
 const isNullEqualityMatcher = (
   matcher: ParsedExpectMatcher,
-): matcher is ParsedEqualityMatcherCall<NullLiteral> =>
-  isParsedEqualityMatcherCall(matcher) && isNullLiteral(matcher.arguments[0]);
+): matcher is ParsedEqualityMatcherCall<MaybeTypeCast<NullLiteral>> =>
+  isParsedEqualityMatcherCall(matcher) &&
+  isNullLiteral(followTypeAssertionChain(matcher.arguments[0]));
 
 export default createRule({
   name: __filename,

src/rules/prefer-to-be-undefined.ts

@@ -6,6 +6,7 @@ import {
   ParsedEqualityMatcherCall,
   ParsedExpectMatcher,
   createRule,
+  followTypeAssertionChain,
   isExpectCall,
   isParsedEqualityMatcherCall,
   parseExpectCall,
@@ -26,13 +27,13 @@ const isUndefinedIdentifier = (
  *
  * @param {ParsedExpectMatcher} matcher
  *
- * @return {matcher is ParsedEqualityMatcherCall<UndefinedIdentifier>}
+ * @return {matcher is ParsedEqualityMatcherCall<MaybeTypeCast<UndefinedIdentifier>>}
  */
 const isUndefinedEqualityMatcher = (
   matcher: ParsedExpectMatcher,
 ): matcher is ParsedEqualityMatcherCall<UndefinedIdentifier> =>
   isParsedEqualityMatcherCall(matcher) &&
-  isUndefinedIdentifier(matcher.arguments[0]);
+  isUndefinedIdentifier(followTypeAssertionChain(matcher.arguments[0]));
 
 export default createRule({
   name: __filename,

src/rules/prefer-to-contain.ts

@@ -11,6 +11,7 @@ import {
   ParsedEqualityMatcherCall,
   ParsedExpectMatcher,
   createRule,
+  followTypeAssertionChain,
   hasOnlyOneArgument,
   isExpectCall,
   isParsedEqualityMatcherCall,
@@ -45,7 +46,7 @@ const isBooleanEqualityMatcher = (
   matcher: ParsedExpectMatcher,
 ): matcher is ParsedBooleanEqualityMatcherCall =>
   isParsedEqualityMatcherCall(matcher) &&
-  isBooleanLiteral(matcher.arguments[0]);
+  isBooleanLiteral(followTypeAssertionChain(matcher.arguments[0]));
 
 type FixableIncludesCallExpression = KnownCallExpression<'includes'> &
   CallExpressionWithSingleArgument;

src/rules/utils.ts

@@ -15,6 +15,35 @@ export const createRule = ESLintUtils.RuleCreator(name => {
   return `${REPO_URL}/blob/v${version}/docs/rules/${ruleName}.md`;
 });
 
+export type MaybeTypeCast<Expression extends TSESTree.Expression> =
+  | TSTypeCastExpression<Expression>
+  | Expression;
+
+export type TSTypeCastExpression<
+  Expression extends TSESTree.Expression = TSESTree.Expression
+> = AsExpressionChain<Expression> | TypeAssertionChain<Expression>;
+
+interface AsExpressionChain<
+  Expression extends TSESTree.Expression = TSESTree.Expression
+> extends TSESTree.TSAsExpression {
+  expression: AsExpressionChain<Expression> | Expression;
+}
+
+interface TypeAssertionChain<
+  Expression extends TSESTree.Expression = TSESTree.Expression
+> extends TSESTree.TSTypeAssertion {
+  // expression: TypeAssertionChain<Expression> | Expression;
+  expression: any; // https://github.com/typescript-eslint/typescript-eslint/issues/802
+}
+
+export const followTypeAssertionChain = (
+  expression: TSESTree.Expression | TSTypeCastExpression,
+): TSESTree.Expression =>
+  expression.type === AST_NODE_TYPES.TSAsExpression ||
+  expression.type === AST_NODE_TYPES.TSTypeAssertion
+    ? followTypeAssertionChain(expression.expression)
+    : expression;
+
 /**
  * A `Literal` with a `value` of type `string`.
  */