fix: adds function expression to functionRegex function (#549)

* fix: add check for js function expressions in functionRegex

* fix: add tests

* fix: lint errors

* change expression name

Author: nafiudanlawal

packages/helpers/lib/index.ts

@@ -264,7 +264,18 @@ export function functionRegex(
   const arrowFuncRegEx = includeBody
     ? `${arrowFuncREHead}${arrowFuncREBody}`
     : `${arrowFuncREHead}`;
-  return new RegExp(`(${capture ? "" : "?:"}${funcRegEx}|${arrowFuncRegEx})`);
+
+  const anonymousFunctionName = funcName
+    ? `(let|const|var)?\\s?${escapeRegExp(funcName)}\\s*=\\s*function\\s*`
+    : "";
+  const anonymousFuncREHead = `${anonymousFunctionName}\\(\\s*${params}\\s*\\)\\s*\\{`;
+  const anonymousFuncRegEx = includeBody
+    ? `${anonymousFuncREHead}${funcREBody}`
+    : `${anonymousFuncREHead}`;
+
+  return new RegExp(
+    `(${capture ? "" : "?:"}${funcRegEx}|${arrowFuncRegEx}|${anonymousFuncRegEx})`,
+  );
 }
 
 function _permutations(permutation: (string | RegExp)[]) {

packages/tests/curriculum-helper.test.tsx

@@ -670,6 +670,51 @@ describe("functionRegex", () => {
     expect(funcRE.test(code)).toBe(true);
     expect(code.match(funcRE)![0]).toBe("const naomi = (love) => ");
   });
+
+  it("matches named anonymous function", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName, ["arg1"]);
+    expect(regEx.test("myFunc = function(arg1){}")).toBe(true);
+  });
+  it("matches named anonymous function without parameters", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName);
+    expect(regEx.test("myFunc = function(){ }")).toBe(true);
+  });
+  it("does not match named anonymous function with different name", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName);
+    expect(regEx.test("notMyFunc = function(arg1){ }")).toBe(false);
+  });
+
+  it("matches named anonymous function with arguments and a body", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName, ["arg1", "arg2"]);
+    expect(
+      regEx.test("myFunc = function(arg1, arg2){\n console.log()\n}"),
+    ).toBe(true);
+  });
+
+  it("does not match named anonymous function with different arguments", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName, ["arg1", "arg2"]);
+    expect(regEx.test("myFunc = function(arg1, arg3){}")).toBe(false);
+  });
+  it("matches const named anonymous function declarations if they are present", () => {
+    const regEx = functionRegex("myFunc", ["arg1", "arg2"]);
+    const func = "const myFunc = function(arg1, arg2) {}";
+    const match = func.match(regEx);
+    expect(match).not.toBeNull();
+    expect(match![0]).toBe(func);
+  });
+  it("can capture named anonymous function", () => {
+    const funcName = "myFunc";
+    const regEx = functionRegex(funcName, ["arg1", "arg2"], { capture: true });
+    const func = "myFunc = function(arg1, arg2){return arg1 + arg2}";
+    const match = func.match(regEx);
+    expect(match).not.toBeNull();
+    expect(match![1]).toBe(func);
+  });
 });
 
 describe("prepTestComponent", () => {