[Refactor] add AST util isFunctionLike()

Author: nix6839

lib/util/ast.js

@@ -232,6 +232,15 @@ function isFunction(node) {
   return node.type === 'FunctionExpression' || node.type === 'FunctionDeclaration';
 }
 
+/**
+ * Checks if node is a function declaration or expression or arrow function.
+ * @param {ASTNode} node The node to check
+ * @return {Boolean} true if it's a function-like
+ */
+function isFunctionLike(node) {
+  return node.type === 'FunctionDeclaration' || isFunctionLikeExpression(node);
+}
+
 /**
  * Checks if the node is a class.
  * @param {ASTNode} node The node to check
@@ -432,6 +441,7 @@ module.exports = {
   isClass,
   isFunction,
   isFunctionLikeExpression,
+  isFunctionLike,
   inConstructor,
   isNodeFirstInLine,
   unwrapTSAsExpression,

tests/util/ast.js

@@ -7,6 +7,7 @@ const espree = require('espree');
 const ast = require('../../lib/util/ast');
 
 const traverseReturns = ast.traverseReturns;
+const isFunctionLike = ast.isFunctionLike;
 
 const DEFAULT_CONFIG = {
   ecmaVersion: 6,
@@ -101,4 +102,76 @@ describe('ast', () => {
       });
     });
   });
+
+  describe('isFunctionLike()', () => {
+    it('FunctionDeclaration should return true', () => {
+      const node1 = parseCode(`
+        function foo(bar) {
+          const asdf = () => 'zxcv';
+          return asdf;
+        }
+      `);
+      assert.strictEqual(isFunctionLike(node1), true);
+
+      const node2 = parseCode(`
+        function foo({bar}) {
+          const asdf = () => 'zxcv';
+          console.log(bar);
+          return '5'
+        }
+      `);
+      assert.strictEqual(isFunctionLike(node2), true);
+    });
+
+    it('FunctionExpression should return true', () => {
+      const node1 = parseCode(`
+        const foo = function(bar) {
+          return () => 'zxcv';
+        }
+      `).declarations[0].init;
+      assert.strictEqual(isFunctionLike(node1), true);
+
+      const node2 = parseCode(`
+        const foo = function ({bar}) {
+          return '5';
+        }
+      `).declarations[0].init;
+      assert.strictEqual(isFunctionLike(node2), true);
+    });
+
+    it('ArrowFunctionExpression should return true', () => {
+      const node1 = parseCode(`
+        (bar) => {
+          return () => 'zxcv';
+        }
+      `).expression;
+      assert.strictEqual(isFunctionLike(node1), true);
+
+      const node2 = parseCode(`
+        ({bar}) => '5';
+      `).expression;
+      assert.strictEqual(isFunctionLike(node2), true);
+
+      const node3 = parseCode(`
+        bar => '5';
+      `).expression;
+      assert.strictEqual(isFunctionLike(node3), true);
+    });
+
+    it('Non-functions should return false', () => {
+      const node1 = parseCode(`
+        class bar {
+          a() {
+            return 'a';
+          }
+        }
+      `);
+      assert.strictEqual(isFunctionLike(node1), false);
+
+      const node2 = parseCode(`
+        const a = 5;
+      `);
+      assert.strictEqual(isFunctionLike(node2), false);
+    });
+  });
 });