diff --git a/remix-tests/src/compiler.ts b/remix-tests/src/compiler.ts
index 34721198fa..28f768f260 100644
--- a/remix-tests/src/compiler.ts
+++ b/remix-tests/src/compiler.ts
@@ -72,7 +72,16 @@ function processFile(filePath: string, sources: SrcIfc, isRoot: boolean = false)
 const userAgent = (typeof (navigator) !== 'undefined') && navigator.userAgent ? navigator.userAgent.toLowerCase() : '-'
 const isBrowser = !(typeof (window) === 'undefined' || userAgent.indexOf(' electron/') > -1)
 
-// TODO: replace this with remix's own compiler code
+/**
+ * @dev Compile file or files before running tests (used for CLI execution)
+ * @param filename Name of file
+ * @param isDirectory True, if path is a directory
+ * @param opts Options
+ * @param cb Callback
+ * 
+ * TODO: replace this with remix's own compiler code
+ */
+
 export function compileFileOrFiles(filename: string, isDirectory: boolean, opts: any, cb: Function) {
     let compiler: any
     const accounts: string[] = opts.accounts || []
@@ -125,11 +134,20 @@ export function compileFileOrFiles(filename: string, isDirectory: boolean, opts:
                 if (!isBrowser) require('signale').fatal(errors)
                 return cb(errors)
             }
-            cb(err, result.contracts, result.sources)
+            cb(err, result.contracts, result.sources) //return callback with contract details & ASTs
         })
     }
 }
 
+/**
+ * @dev Compile contract source before running tests (used for IDE tests execution)
+ * @param sources sources
+ * @param versionUrl url of selected compiler version to load
+ * @param usingWorker if true, load compiler using web worker
+ * @param importFileCb Import file callback
+ * @param opts Options
+ * @param cb Callback
+ */
 export function compileContractSources(sources: SrcIfc, versionUrl: any, usingWorker: boolean, importFileCb: any, opts: any, cb: Function) {
     let compiler, filepath: string
     const accounts: string[] = opts.accounts || []
@@ -172,6 +190,6 @@ export function compileContractSources(sources: SrcIfc, versionUrl: any, usingWo
             if (!isBrowser) require('signale').fatal(errors)
             return cb(errors)
         }
-        cb(err, result.contracts, result.sources)
+        cb(err, result.contracts, result.sources) // return callback with contract details & ASTs
     })
 }
diff --git a/remix-tests/src/runTestFiles.ts b/remix-tests/src/runTestFiles.ts
index a4d283c21f..f0b2e5f1f1 100644
--- a/remix-tests/src/runTestFiles.ts
+++ b/remix-tests/src/runTestFiles.ts
@@ -8,6 +8,14 @@ import Web3 = require('web3')
 import { compileFileOrFiles } from './compiler'
 import { deployAll } from './deployer'
 
+/**
+ * @dev run test contract files (used for CLI)
+ * @param filepath Path of file
+ * @param isDirectory True, if path is a directory
+ * @param web3 Web3
+ * @param opts Options
+ */
+
 export function runTestFiles(filepath: string, isDirectory: boolean, web3: Web3, opts?: object) {
     opts = opts || {}
     let sourceASTs: any = {}
@@ -46,6 +54,7 @@ export function runTestFiles(filepath: string, isDirectory: boolean, web3: Web3,
             compileFileOrFiles(filepath, isDirectory, { accounts }, next)
         },
         function deployAllContracts (compilationResult, asts, next: Function) {
+            // Extract AST of test contract file source
             for(const filename in asts)
             {
                 if(filename.includes('_test.sol'))
diff --git a/remix-tests/src/runTestSources.ts b/remix-tests/src/runTestSources.ts
index addd437dee..d0fc218d3f 100644
--- a/remix-tests/src/runTestSources.ts
+++ b/remix-tests/src/runTestSources.ts
@@ -4,7 +4,7 @@ require('colors')
 import { compileContractSources } from './compiler'
 import { deployAll } from './deployer'
 import { runTest } from './testRunner'
-import { TestResultInterface, ResultsInterface } from './types'
+import { TestResultInterface } from './types'
 
 import Web3 = require('web3')
 import { Provider } from 'remix-simulator'
@@ -18,6 +18,17 @@ const createWeb3Provider = async function () {
     return web3
 }
 
+/**
+ * @dev Run tests from source of a test contract file (used for IDE)
+ * @param contractSources Sources of contract
+ * @param versionUrl url of selected compiler version to load
+ * @param usingWorker if true, load compiler using web worker
+ * @param testCallback Test callback
+ * @param resultCallback Result Callback
+ * @param finalCallback Final Callback
+ * @param importFileCb Import file callback
+ * @param opts Options
+ */
 export async function runTestSources(contractSources, versionUrl, usingWorker, testCallback, resultCallback, finalCallback, importFileCb, opts) {
     opts = opts || {}
     let sourceASTs: any = {}
diff --git a/remix-tests/src/testRunner.ts b/remix-tests/src/testRunner.ts
index 299a023d0e..b9095b1343 100644
--- a/remix-tests/src/testRunner.ts
+++ b/remix-tests/src/testRunner.ts
@@ -19,26 +19,45 @@ function getOverridedSender (userdoc, signature: string, methodIdentifiers) {
     return fullName && accountIndex ? accountIndex[1] : null
 }
 
-function getAvailableFunctions (fileAST, testContractName) {
-    let contractAST: any[] = fileAST.nodes.filter(node => node.name === testContractName && node.nodeType === 'ContractDefinition')
-    let funcNodes: any[] = contractAST[0].nodes.filter(node => node.kind === 'function' && node.nodeType === "FunctionDefinition")
-    let funcList: string[] = funcNodes.map(node => node.name)
+/**
+ * @dev returns functions of a test contract file in same sequence they appear in file (using passed AST)
+ * @param fileAST AST of test contract file source
+ * @param testContractName Name of test contract
+ */
+
+function getAvailableFunctions (fileAST: any, testContractName: string) {
+    const contractAST: any[] = fileAST.nodes.filter(node => node.name === testContractName && node.nodeType === 'ContractDefinition')
+    const funcNodes: any[] = contractAST[0].nodes.filter(node => node.kind === 'function' && node.nodeType === "FunctionDefinition")
+    const funcList: string[] = funcNodes.map(node => node.name)
     return funcList;
 }
 
-function getTestFunctionsInterface (jsonInterface, funcList: string[]) {
-    let resutantInterface: any[] = []
-    let specialFunctions = ['beforeAll', 'beforeEach', 'afterAll', 'afterEach']
+/**
+ * @dev returns ABI of passed method list from passed interface
+ * @param jsonInterface Json Interface
+ * @param funcList Methods to extract the interface of
+ */
+
+function getTestFunctionsInterface (jsonInterface: any, funcList: string[]) {
+    let functionsInterface: any[] = []
+    const specialFunctions = ['beforeAll', 'beforeEach', 'afterAll', 'afterEach']
     for(const func of funcList){
         if(!specialFunctions.includes(func))
-            resutantInterface.push(jsonInterface.find(node => node.type === 'function' && node.name === func))
+            functionsInterface.push(jsonInterface.find(node => node.type === 'function' && node.name === func))
     }
-    return resutantInterface
+    return functionsInterface
 }
 
-function createRunList (jsonInterface, fileAST, testContractName): RunListInterface[] {
-    let availableFunctions = getAvailableFunctions(fileAST, testContractName)
-    let testFunctionsInterface = getTestFunctionsInterface(jsonInterface, availableFunctions)
+/**
+ * @dev Prepare a list of tests to run using test contract file ABI, AST & contract name
+ * @param jsonInterface File JSON interface
+ * @param fileAST File AST
+ * @param testContractName Test contract name
+ */
+
+function createRunList (jsonInterface: any, fileAST: any, testContractName: string): RunListInterface[] {
+    const availableFunctions: string[] = getAvailableFunctions(fileAST, testContractName)
+    const testFunctionsInterface: any[] = getTestFunctionsInterface(jsonInterface, availableFunctions)
 
     let runList: RunListInterface[] = []
 
@@ -46,7 +65,7 @@ function createRunList (jsonInterface, fileAST, testContractName): RunListInterf
         runList.push({ name: 'beforeAll', type: 'internal', constant: false })
     }
 
-    for (let func of testFunctionsInterface) {
+    for (const func of testFunctionsInterface) {
         if (availableFunctions.indexOf('beforeEach') >= 0) {
             runList.push({ name: 'beforeEach', type: 'internal', constant: false })
         }
@@ -64,11 +83,11 @@ function createRunList (jsonInterface, fileAST, testContractName): RunListInterf
 }
 
 export function runTest (testName, testObject: any, contractDetails: any, fileAST: any, opts: any, testCallback: TestCbInterface, resultsCallback: ResultCbInterface) {
-    let runList = createRunList(testObject._jsonInterface, fileAST, testName)
+    const runList: RunListInterface[] = createRunList(testObject._jsonInterface, fileAST, testName)
     let passingNum: number = 0
     let failureNum: number = 0
     let timePassed: number = 0
-    let web3 = new Web3()
+    const web3 = new Web3()
 
     const accts: TestResultInterface = {
       type: 'accountList',
@@ -95,11 +114,11 @@ export function runTest (testName, testObject: any, contractDetails: any, fileAS
         let sendParams
         if (sender) sendParams = { from: sender }
 
-        let method = testObject.methods[func.name].apply(testObject.methods[func.name], [])
-        let startTime = Date.now()
+        const method = testObject.methods[func.name].apply(testObject.methods[func.name], [])
+        const startTime = Date.now()
         if (func.constant) {
             method.call(sendParams).then((result) => {
-                let time = (Date.now() - startTime) / 1000.0
+                const time = (Date.now() - startTime) / 1000.0
                 if (result) {
                     const resp: TestResultInterface = {
                       type: 'testPass',
@@ -126,12 +145,12 @@ export function runTest (testName, testObject: any, contractDetails: any, fileAS
         } else {
             method.send(sendParams).on('receipt', (receipt) => {
                 try {
-                    let time: number = (Date.now() - startTime) / 1000.0
-                    let topic = Web3.utils.sha3('AssertionEvent(bool,string)')
+                    const time: number = (Date.now() - startTime) / 1000.0
+                    const topic = Web3.utils.sha3('AssertionEvent(bool,string)')
                     let testPassed: boolean = false
 
-                    for (let i in receipt.events) {
-                        let event = receipt.events[i]
+                    for (const i in receipt.events) {
+                        const event = receipt.events[i]
                         if (event.raw.topics.indexOf(topic) >= 0) {
                             const testEvent = web3.eth.abi.decodeParameters(['bool', 'string'], event.raw.data)
                             if (!testEvent[0]) {
@@ -168,7 +187,7 @@ export function runTest (testName, testObject: any, contractDetails: any, fileAS
                 }
             }).on('error', function (err: any) {
                 console.error(err)
-                let time: number = (Date.now() - startTime) / 1000.0
+                const time: number = (Date.now() - startTime) / 1000.0
                 const resp: TestResultInterface = {
                     type: 'testFailure',
                     value: changeCase.sentenceCase(func.name),
diff --git a/remix-tests/tests/testRunner.ts b/remix-tests/tests/testRunner.ts
index ff7151bded..9fdceba2ef 100644
--- a/remix-tests/tests/testRunner.ts
+++ b/remix-tests/tests/testRunner.ts
@@ -103,7 +103,7 @@ describe('testRunner', () => {
 
     describe('#runTest', () => {
     describe('test with beforeAll', () => {
-      let filename: string = 'tests/examples_1/simple_storage_test.sol'
+      const filename: string = 'tests/examples_1/simple_storage_test.sol'
 
       before((done) => {
         compileAndDeploy(filename, (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) => {
@@ -134,7 +134,7 @@ describe('testRunner', () => {
     })
 
     describe('test with beforeEach', function () {
-      let filename = 'tests/examples_2/simple_storage_test.sol'
+      const filename: string = 'tests/examples_2/simple_storage_test.sol'
 
       before(function (done) {
         compileAndDeploy(filename, function (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) {
@@ -164,7 +164,7 @@ describe('testRunner', () => {
 
     // Test string equality
     describe('test string equality', function () {
-      let filename = 'tests/examples_3/simple_string_test.sol'
+      const filename: string = 'tests/examples_3/simple_string_test.sol'
 
       before(function (done) {
         compileAndDeploy(filename, function (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) {
@@ -190,7 +190,7 @@ describe('testRunner', () => {
 
     // Test multiple directory import in test contract
     describe('test multiple directory import in test contract', function () {
-      let filename = 'tests/examples_5/test/simple_storage_test.sol'
+      const filename: string = 'tests/examples_5/test/simple_storage_test.sol'
 
       before(function (done) {
         compileAndDeploy(filename, function (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) {
@@ -217,7 +217,7 @@ describe('testRunner', () => {
 
     //Test signed/unsigned integer weight
     describe('test number weight', function () {
-      let filename = 'tests/number/number_test.sol'
+      const filename: string = 'tests/number/number_test.sol'
 
       before(function (done) {
         compileAndDeploy(filename, function (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) {
@@ -237,7 +237,7 @@ describe('testRunner', () => {
 
     // Test Transaction with different sender
     describe('various sender', function () {
-      let filename = 'tests/various_sender/sender_test.sol'
+      const filename: string = 'tests/various_sender/sender_test.sol'
 
       before(function (done) {
         compileAndDeploy(filename, function (_err: Error | null | undefined, compilationData: object, contracts: any, asts: any, accounts: string[]) {