feat(eslint-plugin): add rule no-unsafe-call (#1647)

bradzacher · web-flow · commit 91423e49d191 · 2020-03-03T01:26:29.000-08:00
diff --git a/packages/eslint-plugin/README.md b/packages/eslint-plugin/README.md
@@ -132,6 +132,7 @@ Pro Tip: For larger codebases you may want to consider splitting our linting int
 | [`@typescript-eslint/no-unnecessary-qualifier`](./docs/rules/no-unnecessary-qualifier.md)                             | Warns when a namespace qualifier is unnecessary                                                                         |                    | :wrench: | :thought_balloon: |
 | [`@typescript-eslint/no-unnecessary-type-arguments`](./docs/rules/no-unnecessary-type-arguments.md)                   | Enforces that type arguments will not be used if not required                                                           |                    | :wrench: | :thought_balloon: |
 | [`@typescript-eslint/no-unnecessary-type-assertion`](./docs/rules/no-unnecessary-type-assertion.md)                   | Warns if a type assertion does not change the type of an expression                                                     | :heavy_check_mark: | :wrench: | :thought_balloon: |
+| [`@typescript-eslint/no-unsafe-call`](./docs/rules/no-unsafe-call.md)                                                 | Disallows calling an any type value                                                                                     |                    |          | :thought_balloon: |
 | [`@typescript-eslint/no-unsafe-member-access`](./docs/rules/no-unsafe-member-access.md)                               | Disallows member access on any typed variables                                                                          |                    |          | :thought_balloon: |
 | [`@typescript-eslint/no-unsafe-return`](./docs/rules/no-unsafe-return.md)                                             | Disallows returning any from a function                                                                                 |                    |          | :thought_balloon: |
 | [`@typescript-eslint/no-unused-vars-experimental`](./docs/rules/no-unused-vars-experimental.md)                       | Disallow unused variables and arguments                                                                                 |                    |          | :thought_balloon: |
diff --git a/packages/eslint-plugin/docs/rules/no-unsafe-call.md b/packages/eslint-plugin/docs/rules/no-unsafe-call.md
@@ -0,0 +1,41 @@
+# Disallows calling an any type value (`no-unsafe-call`)
+
+Despite your best intentions, the `any` type can sometimes leak into your codebase.
+Member access on `any` typed variables is not checked at all by TypeScript, so it creates a potential safety hole, and source of bugs in your codebase.
+
+## Rule Details
+
+This rule disallows calling any variable that is typed as `any`.
+
+Examples of **incorrect** code for this rule:
+
+```ts
+declare const anyVar: any;
+declare const nestedAny: { prop: any };
+
+anyVar();
+anyVar.a.b();
+
+nestedAny.prop();
+nestedAny.prop['a']();
+
+new anyVar();
+new nestedAny.prop();
+```
+
+Examples of **correct** code for this rule:
+
+```ts
+declare const properlyTyped: { prop: { a: () => void } };
+
+nestedAny.prop.a();
+
+(() => {})();
+
+new Map();
+```
+
+## Related to
+
+- [`no-explicit-any`](./no-explicit-any.md)
+- TSLint: [`no-unsafe-any`](https://palantir.github.io/tslint/rules/no-unsafe-any/)
diff --git a/packages/eslint-plugin/src/configs/all.json b/packages/eslint-plugin/src/configs/all.json
@@ -61,6 +61,7 @@
     "@typescript-eslint/no-unnecessary-qualifier": "error",
     "@typescript-eslint/no-unnecessary-type-arguments": "error",
     "@typescript-eslint/no-unnecessary-type-assertion": "error",
+    "@typescript-eslint/no-unsafe-call": "error",
     "@typescript-eslint/no-unsafe-member-access": "error",
     "@typescript-eslint/no-unsafe-return": "error",
     "no-unused-expressions": "off",
diff --git a/packages/eslint-plugin/src/rules/index.ts b/packages/eslint-plugin/src/rules/index.ts
@@ -53,6 +53,7 @@ import noUnnecessaryCondition from './no-unnecessary-condition';
 import noUnnecessaryQualifier from './no-unnecessary-qualifier';
 import noUnnecessaryTypeArguments from './no-unnecessary-type-arguments';
 import noUnnecessaryTypeAssertion from './no-unnecessary-type-assertion';
+import noUnsafeCall from './no-unsafe-call';
 import noUnsafeMemberAccess from './no-unsafe-member-access';
 import noUnsafeReturn from './no-unsafe-return';
 import noUntypedPublicSignature from './no-untyped-public-signature';
@@ -146,6 +147,7 @@ export default {
   'no-unnecessary-qualifier': noUnnecessaryQualifier,
   'no-unnecessary-type-arguments': noUnnecessaryTypeArguments,
   'no-unnecessary-type-assertion': noUnnecessaryTypeAssertion,
+  'no-unsafe-call': noUnsafeCall,
   'no-unsafe-member-access': noUnsafeMemberAccess,
   'no-unsafe-return': noUnsafeReturn,
   'no-untyped-public-signature': noUntypedPublicSignature,
diff --git a/packages/eslint-plugin/src/rules/no-unsafe-call.ts b/packages/eslint-plugin/src/rules/no-unsafe-call.ts
@@ -0,0 +1,52 @@
+import { TSESTree } from '@typescript-eslint/experimental-utils';
+import * as util from '../util';
+
+type MessageIds = 'unsafeCall' | 'unsafeNew';
+
+export default util.createRule<[], MessageIds>({
+  name: 'no-unsafe-call',
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'Disallows calling an any type value',
+      category: 'Possible Errors',
+      recommended: false,
+      requiresTypeChecking: true,
+    },
+    messages: {
+      unsafeCall: 'Unsafe call of an any typed value',
+      unsafeNew: 'Unsafe construction of an any type value',
+    },
+    schema: [],
+  },
+  defaultOptions: [],
+  create(context) {
+    const { program, esTreeNodeToTSNodeMap } = util.getParserServices(context);
+    const checker = program.getTypeChecker();
+
+    function checkCall(
+      node:
+        | TSESTree.CallExpression
+        | TSESTree.OptionalCallExpression
+        | TSESTree.NewExpression,
+      reportingNode: TSESTree.Expression = node.callee,
+      messageId: MessageIds = 'unsafeCall',
+    ): void {
+      const tsNode = esTreeNodeToTSNodeMap.get(node.callee);
+      const type = checker.getTypeAtLocation(tsNode);
+      if (util.isTypeAnyType(type)) {
+        context.report({
+          node: reportingNode,
+          messageId: messageId,
+        });
+      }
+    }
+
+    return {
+      'CallExpression, OptionalCallExpression': checkCall,
+      NewExpression(node): void {
+        checkCall(node, node, 'unsafeNew');
+      },
+    };
+  },
+});
diff --git a/packages/eslint-plugin/tests/rules/no-unsafe-call.test.ts b/packages/eslint-plugin/tests/rules/no-unsafe-call.test.ts
@@ -0,0 +1,106 @@
+import rule from '../../src/rules/no-unsafe-call';
+import {
+  RuleTester,
+  batchedSingleLineTests,
+  getFixturesRootDir,
+} from '../RuleTester';
+
+const ruleTester = new RuleTester({
+  parser: '@typescript-eslint/parser',
+  parserOptions: {
+    project: './tsconfig.json',
+    tsconfigRootDir: getFixturesRootDir(),
+  },
+});
+
+ruleTester.run('no-unsafe-call', rule, {
+  valid: [
+    'function foo(x: () => void) { x() }',
+    'function foo(x?: { a: () => void }) { x?.a() }',
+    'function foo(x: { a?: () => void }) { x.a?.() }',
+    'new Map()',
+  ],
+  invalid: [
+    ...batchedSingleLineTests({
+      code: `
+function foo(x: any) { x() }
+function foo(x: any) { x?.() }
+function foo(x: any) { x.a.b.c.d.e.f.g() }
+function foo(x: any) { x.a.b.c.d.e.f.g?.() }
+      `,
+      errors: [
+        {
+          messageId: 'unsafeCall',
+          line: 2,
+          column: 24,
+          endColumn: 25,
+        },
+        {
+          messageId: 'unsafeCall',
+          line: 3,
+          column: 24,
+          endColumn: 25,
+        },
+        {
+          messageId: 'unsafeCall',
+          line: 4,
+          column: 24,
+          endColumn: 39,
+        },
+        {
+          messageId: 'unsafeCall',
+          line: 5,
+          column: 24,
+          endColumn: 39,
+        },
+      ],
+    }),
+    ...batchedSingleLineTests({
+      code: `
+function foo(x: { a: any }) { x.a() }
+function foo(x: { a: any }) { x?.a() }
+function foo(x: { a: any }) { x.a?.() }
+      `,
+      errors: [
+        {
+          messageId: 'unsafeCall',
+          line: 2,
+          column: 31,
+          endColumn: 34,
+        },
+        {
+          messageId: 'unsafeCall',
+          line: 3,
+          column: 31,
+          endColumn: 35,
+        },
+        {
+          messageId: 'unsafeCall',
+          line: 4,
+          column: 31,
+          endColumn: 34,
+        },
+      ],
+    }),
+    ...batchedSingleLineTests({
+      code: `
+function foo(x: any) { new x() }
+function foo(x: { a: any }) { new x.a() }
+      `,
+      errors: [
+        {
+          messageId: 'unsafeNew',
+          line: 2,
+          column: 24,
+          endColumn: 31,
+        },
+        {
+          messageId: 'unsafeNew',
+          line: 3,
+          column: 31,
+          endColumn: 40,
+        },
+      ],
+    }),
+  ],
+});
