do not reload compiler for same config

libs/remix-tests/package.json

@@ -49,6 +49,7 @@
     "color-support": "^1.1.3",
     "colors": "^1.1.2",
     "commander": "^2.13.0",
+    "deep-equal": "^1.0.1",
     "ethereumjs-util": "^7.0.10",
     "ethers": "^5.4.2",
     "ethjs-util": "^0.1.6",

libs/remix-tests/src/compiler.ts

@@ -170,8 +170,7 @@ export function compileFileOrFiles (filename: string, isDirectory: boolean, opts
  * @param opts Options
  * @param cb Callback
  */
-export function compileContractSources (sources: SrcIfc, compilerConfig: CompilerConfiguration, importFileCb: any, opts: any, cb): void {
-  let compiler
+export function compileContractSources (sources: SrcIfc, compiler: any, opts: any, cb): void {
   const filepath = opts.testFilePath || ''
   const testFileImportRegEx = /^(import)\s['"](remix_tests.sol|tests.sol)['"];/gm
 
@@ -184,18 +183,6 @@ export function compileContractSources (sources: SrcIfc, compilerConfig: Compile
   }
 
   async.waterfall([
-    function loadCompiler (next) {
-      const { currentCompilerUrl, evmVersion, optimize, runs, usingWorker } = compilerConfig
-      compiler = new RemixCompiler(importFileCb)
-      compiler.set('evmVersion', evmVersion)
-      compiler.set('optimize', optimize)
-      compiler.set('runs', runs)
-      compiler.loadVersion(usingWorker, currentCompilerUrl)
-      // @ts-ignore
-      compiler.event.register('compilerLoaded', this, (version) => {
-        next()
-      })
-    },
     function doCompilation (next) {
       // @ts-ignore
       compiler.event.register('compilationFinished', this, (success, data, source) => {

libs/remix-tests/src/runTestSources.ts

@@ -1,4 +1,6 @@
 import async, { ErrorCallback } from 'async'
+import deepequal from 'deep-equal'
+import { Compiler as RemixCompiler } from '@remix-project/remix-solidity'
 import { compileContractSources, writeTestAccountsContract } from './compiler'
 import { deployAll } from './deployer'
 import { runTest } from './testRunner'
@@ -16,6 +18,8 @@ export class UnitTestRunner {
   accountsLibCode
   testsAccounts: string[] | null
   web3
+  compiler
+  compilerConfig
 
   constructor () {
     this.event = new EventEmitter()
@@ -53,7 +57,22 @@ export class UnitTestRunner {
 
     async.waterfall([
       (next) => {
-        compileContractSources(contractSources, compilerConfig, importFileCb, { accounts: this.testsAccounts, testFilePath: opts.testFilePath, event: this.event }, next)
+        if (!deepequal(this.compilerConfig, compilerConfig)) {
+          this.compilerConfig = compilerConfig
+          const { currentCompilerUrl, evmVersion, optimize, runs, usingWorker } = compilerConfig
+          this.compiler = new RemixCompiler(importFileCb)
+          this.compiler.set('evmVersion', evmVersion)
+          this.compiler.set('optimize', optimize)
+          this.compiler.set('runs', runs)
+          this.compiler.loadVersion(usingWorker, currentCompilerUrl)
+          // @ts-ignore
+          this.compiler.event.register('compilerLoaded', this, (version) => {
+            next()
+          })
+        } else next()
+      },
+      (next) => {
+        compileContractSources(contractSources, this.compiler, { accounts: this.testsAccounts, testFilePath: opts.testFilePath, event: this.event }, next)
       },
       (compilationResult: compilationInterface, asts: ASTInterface, next) => {
         for (const filename in asts) {