Avoid cleaning up solidity test artifacts on compile task

Author: antico5

.changeset/forty-steaks-live.md

@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Stop solidity tests being recompiled unnecessarily ([#7116](https://github.com/NomicFoundation/hardhat/issues/7116))

v-next/hardhat/src/internal/builtin-plugins/solidity/build-system/build-system.ts

@@ -84,6 +84,7 @@ export interface SolidityBuildSystemOptions {
   readonly soliditySourcesPaths: string[];
   readonly artifactsPath: string;
   readonly cachePath: string;
+  readonly solidityTestsPath: string;
 }
 
 export class SolidityBuildSystemImplementation implements SolidityBuildSystem {
@@ -290,6 +291,8 @@ export class SolidityBuildSystemImplementation implements SolidityBuildSystem {
     rootFilePaths: string[],
     options?: GetCompilationJobsOptions,
   ): Promise<CompilationJobCreationError | GetCompilationJobsResult> {
+    const isolated = options?.isolated ?? false;
+
     await this.#downloadConfiguredCompilers(options?.quiet);
 
     const dependencyGraph = await buildDependencyGraph(
@@ -397,7 +400,7 @@ export class SolidityBuildSystemImplementation implements SolidityBuildSystem {
         options?.force === true ||
         cacheResult === undefined ||
         cacheResult.jobHash !== jobHash ||
-        cacheResult.isolated !== options?.isolated
+        cacheResult.isolated !== isolated
       ) {
         rootFilesToCompile.add(rootFile);
         continue;
@@ -424,10 +427,7 @@ export class SolidityBuildSystemImplementation implements SolidityBuildSystem {
       }
     }
 
-    if (
-      options?.isolated !== true &&
-      shouldMergeCompilationJobs(buildProfileName)
-    ) {
+    if (!isolated && shouldMergeCompilationJobs(buildProfileName)) {
       // non-isolated mode
       log(`Merging compilation jobs`);
 
@@ -702,6 +702,20 @@ export class SolidityBuildSystemImplementation implements SolidityBuildSystem {
     )) {
       const relativePath = path.relative(this.#options.artifactsPath, file);
 
+      const testDirectorySubpath = path.relative(
+        this.#options.projectRoot,
+        this.#options.solidityTestsPath,
+      );
+      const hasTestFileExtension = file.endsWith(".t.sol");
+      const isInsideTestFolder = relativePath.startsWith(
+        testDirectorySubpath + path.sep,
+      );
+
+      // Skip test artifacts, since our full compilation doesn't include them, they would incorrectly be marked for deletion
+      if (hasTestFileExtension || isInsideTestFolder) {
+        continue;
+      }
+
       if (!userSourceNamesSet.has(relativePath)) {
         await remove(file);
       }

v-next/hardhat/src/internal/builtin-plugins/solidity/hook-handlers/hre.ts

@@ -120,6 +120,7 @@ export default async (): Promise<Partial<HardhatRuntimeEnvironmentHooks>> => {
         soliditySourcesPaths: hre.config.paths.sources.solidity,
         artifactsPath: hre.config.paths.artifacts,
         cachePath: hre.config.paths.cache,
+        solidityTestsPath: hre.config.paths.tests.solidity,
       });
     },
   };

v-next/hardhat/test/internal/builtin-plugins/solidity/build-system/build-system.ts

@@ -107,6 +107,7 @@ describe(
         soliditySourcesPaths: [path.join(process.cwd(), "contracts")],
         artifactsPath: expectedArtifactsPath,
         cachePath: expectedCachePath,
+        solidityTestsPath: path.join(process.cwd(), "tests"),
       });
       const rootFilePaths = await solidity.getRootFilePaths();
       await solidity.build(rootFilePaths, {
@@ -129,6 +130,7 @@ describe(
         soliditySourcesPaths: [path.join(process.cwd(), "contracts")],
         artifactsPath: actualArtifactsPath,
         cachePath: actualCachePath,
+        solidityTestsPath: path.join(process.cwd(), "tests"),
       });
     });