fix(eslint-plugin): [unbound-method] handling destructuring (typescript-eslint#2228)

Author: yeonjuan

packages/eslint-plugin/src/rules/unbound-method.ts

@@ -99,7 +99,7 @@ const nativelyBoundMembers = SUPPORTED_GLOBALS.map(namespace => {
   .reduce((arr, names) => arr.concat(names), [])
   .filter(name => !nativelyNotBoundMembers.has(name));
 
-const isMemberNotImported = (
+const isNotImported = (
   symbol: ts.Symbol,
   currentSourceFile: ts.SourceFile | undefined,
 ): boolean => {
@@ -176,7 +176,7 @@ export default util.createRule<Options, MessageIds>({
         if (
           objectSymbol &&
           nativelyBoundMembers.includes(getMemberFullName(node)) &&
-          isMemberNotImported(objectSymbol, currentSourceFile)
+          isNotImported(objectSymbol, currentSourceFile)
         ) {
           return;
         }
@@ -191,6 +191,48 @@ export default util.createRule<Options, MessageIds>({
           });
         }
       },
+      'VariableDeclarator, AssignmentExpression'(
+        node: TSESTree.VariableDeclarator | TSESTree.AssignmentExpression,
+      ): void {
+        const [idNode, initNode] =
+          node.type === AST_NODE_TYPES.VariableDeclarator
+            ? [node.id, node.init]
+            : [node.left, node.right];
+
+        if (initNode && idNode.type === AST_NODE_TYPES.ObjectPattern) {
+          const tsNode = parserServices.esTreeNodeToTSNodeMap.get(initNode);
+          const rightSymbol = checker.getSymbolAtLocation(tsNode);
+          const initTypes = checker.getTypeAtLocation(tsNode);
+
+          const notImported =
+            rightSymbol && isNotImported(rightSymbol, currentSourceFile);
+
+          idNode.properties.forEach(property => {
+            if (
+              property.type === AST_NODE_TYPES.Property &&
+              property.key.type === AST_NODE_TYPES.Identifier
+            ) {
+              if (
+                notImported &&
+                util.isIdentifier(initNode) &&
+                nativelyBoundMembers.includes(
+                  `${initNode.name}.${property.key.name}`,
+                )
+              ) {
+                return;
+              }
+
+              const symbol = initTypes.getProperty(property.key.name);
+              if (symbol && isDangerousMethod(symbol, ignoreStatic)) {
+                context.report({
+                  messageId: 'unbound',
+                  node,
+                });
+              }
+            }
+          });
+        }
+      },
     };
   },
 });

packages/eslint-plugin/tests/rules/unbound-method.test.ts

@@ -228,6 +228,35 @@ class A {
   }
 }
     `,
+    'const { parseInt } = Number;',
+    'const { log } = console;',
+    `
+let parseInt;
+({ parseInt } = Number);
+    `,
+    `
+let log;
+({ log } = console);
+    `,
+    `
+const foo = {
+  bar: 'bar',
+};
+const { bar } = foo;
+    `,
+    `
+class Foo {
+  unbnound() {}
+  bar = 4;
+}
+const { bar } = new Foo();
+    `,
+    `
+class Foo {
+  bound = () => 'foo';
+}
+const { bound } = new Foo();
+    `,
   ],
   invalid: [
     {
@@ -288,8 +317,8 @@ function foo(arg: ContainsMethods | null) {
       'const unbound = instance.unbound;',
       'const unboundStatic = ContainsMethods.unboundStatic;',
 
-      'const { unbound } = instance.unbound;',
-      'const { unboundStatic } = ContainsMethods.unboundStatic;',
+      'const { unbound } = instance;',
+      'const { unboundStatic } = ContainsMethods;',
 
       '<any>instance.unbound;',
       'instance.unbound as any;',
@@ -384,5 +413,113 @@ const unbound = new Foo().unbound;
         },
       ],
     },
+    {
+      code: `
+class Foo {
+  unbound() {}
+}
+const { unbound } = new Foo();
+      `,
+      errors: [
+        {
+          line: 5,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+class Foo {
+  unbound = function () {};
+}
+const { unbound } = new Foo();
+      `,
+      errors: [
+        {
+          line: 5,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+class Foo {
+  unbound() {}
+}
+let unbound;
+({ unbound } = new Foo());
+      `,
+      errors: [
+        {
+          line: 6,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+class Foo {
+  unbound = function () {};
+}
+let unbound;
+({ unbound } = new Foo());
+      `,
+      errors: [
+        {
+          line: 6,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+class CommunicationError {
+  foo() {}
+}
+const { foo } = CommunicationError.prototype;
+      `,
+      errors: [
+        {
+          line: 5,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+class CommunicationError {
+  foo() {}
+}
+let foo;
+({ foo } = CommunicationError.prototype);
+      `,
+      errors: [
+        {
+          line: 6,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: `
+import { console } from './class';
+const { log } = console;
+      `,
+      errors: [
+        {
+          line: 3,
+          messageId: 'unbound',
+        },
+      ],
+    },
+    {
+      code: 'const { all } = Promise;',
+      errors: [
+        {
+          line: 1,
+          messageId: 'unbound',
+        },
+      ],
+    },
   ],
 });