Add support for ESM test files

Author: schaable

.changeset/friendly-dryers-mix.md

@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Added support for ESM test files

packages/hardhat-core/src/builtin-tasks/test.ts

@@ -7,7 +7,11 @@ import { HARDHAT_NETWORK_NAME } from "../internal/constants";
 import { subtask, task } from "../internal/core/config/config-env";
 import { HardhatError } from "../internal/core/errors";
 import { ERRORS } from "../internal/core/errors-list";
-import { isRunningWithTypescript } from "../internal/core/typescript-support";
+import {
+  isJavascriptFile,
+  isRunningWithTypescript,
+  isTypescriptFile,
+} from "../internal/core/typescript-support";
 import { getForkCacheDirPath } from "../internal/hardhat-network/provider/utils/disk-cache";
 import { showForkRecommendationsBannerIfNecessary } from "../internal/hardhat-network/provider/utils/fork-recomendations-banner";
 import { pluralize } from "../internal/util/strings";
@@ -40,7 +44,7 @@ subtask(TASK_TEST_GET_TEST_FILES)
 
     const jsFiles = await getAllFilesMatching(
       config.paths.tests,
-      (f) => f.endsWith(".js") || f.endsWith(".cjs") || f.endsWith(".mjs")
+      isJavascriptFile
     );
 
     if (!isRunningWithTypescript(config)) {
@@ -49,7 +53,7 @@ subtask(TASK_TEST_GET_TEST_FILES)
 
     const tsFiles = await getAllFilesMatching(
       config.paths.tests,
-      (f) => f.endsWith(".ts") || f.endsWith(".cts")
+      isTypescriptFile
     );
 
     return [...jsFiles, ...tsFiles];

packages/hardhat-core/src/internal/core/typescript-support.ts

@@ -13,14 +13,14 @@ let cachedIsTypescriptSupported: boolean | undefined;
  */
 export function willRunWithTypescript(configPath?: string): boolean {
   const config = resolveConfigPath(configPath);
-  return isTypescriptFile(config);
+  return isNonEsmTypescriptFile(config);
 }
 
 /**
  * Returns true if an Hardhat is already running with typescript.
  */
 export function isRunningWithTypescript(config: HardhatConfig): boolean {
-  return isTypescriptFile(config.paths.configFile);
+  return isNonEsmTypescriptFile(config.paths.configFile);
 }
 
 export function isTypescriptSupported() {
@@ -80,6 +80,14 @@ export function loadTsNode(
   require(tsNodeRequirement);
 }
 
-function isTypescriptFile(path: string): boolean {
-  return path.endsWith(".ts") || path.endsWith(".cts");
+function isNonEsmTypescriptFile(path: string): boolean {
+  return /\.(ts|cts)$/i.test(path);
+}
+
+export function isTypescriptFile(path: string): boolean {
+  return /\.(ts|cts|mts)$/i.test(path);
+}
+
+export function isJavascriptFile(path: string): boolean {
+  return /\.(js|cjs|mjs)$/i.test(path);
 }