feat: add test-util to append data to file

Author: hemal7735

test/test-utils.test.js

@@ -1,6 +1,8 @@
 "use strict";
 
-const{ extractHash }=require("./testUtils");
+const{ extractHash, appendDataIfFileExists }=require("./testUtils");
+const{ writeFileSync, unlinkSync, readFileSync }=require("fs");
+const{ resolve }=require("path");
 
 describe("extractHash functionality",()=>{
 it("should throw Error if there is empty string",()=>{
@@ -101,3 +103,29 @@ Child ${config2Name}:
 expect(hashInfo.config[1]).toEqual({name: config2Name,hash: config2Hash});
 });
 });
+
+describe("appendFile functionality",()=>{
+describe("positive test-cases",()=>{
+constjunkFile=resolve(__dirname,"junkFile.js");
+
+beforeEach(()=>{
+writeFileSync(junkFile,"");
+});
+afterEach(()=>{
+unlinkSync(junkFile);
+});
+it("should append data to file if file exists",()=>{
+constexpectedData="//junk comment";
+appendDataIfFileExists(__dirname,junkFile,expectedData);
+constactualData=readFileSync(junkFile).toString();
+
+expect(actualData).toBe(expectedData);
+});
+});
+
+describe("negative test-cases",()=>{
+it("should throw error if file does not exist",()=>{
+expect(()=>appendDataIfFileExists(__dirname,"does-not-exist.js","junk data")).toThrowError();
+});
+});
+});

test/testUtils.js

@@ -148,4 +148,23 @@ function extractHash(stdout) {
 returnhashInfo;
 }
 
-module.exports={ run, runWatch, extractHash, extractSummary };
+/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
+/**
+ *
+ * @param {*} testCase - testCase directory
+ * @param {*} file - file relative to testCase
+ * @param {*} data - data to append
+ * @throws - throw an Error if file does not exist
+ */
+functionappendDataIfFileExists(testCase,file,data){
+const{ existsSync, appendFileSync }=require("fs");
+
+constfilePath=path.resolve(testCase,file);
+if(existsSync(filePath)){
+appendFileSync(filePath,data);
+}else{
+thrownewError(`Oops! ${filePath} does not exist!`);
+}
+}
+
+module.exports={ run, runWatch, extractHash, extractSummary, appendDataIfFileExists };