Add splitTestsCompilation solidity setting (8): Mocha updates

packages/hardhat-mocha/src/task-action.ts

@@ -82,9 +82,8 @@ const testWithHardhat: NewTaskActionFunction<TestActionArguments> = async (
   perf.startPhase("Build");
 
   if (!noCompile) {
-    await hre.tasks.getTask("build").run({
-      noTests: true,
-    });
+    const noTests = hre.config.solidity.splitTestsCompilation;
+    await hre.tasks.getTask("build").run({ noTests });
     console.log();
   }
 

packages/hardhat-mocha/test/index.ts

@@ -1,3 +1,5 @@
+import type { HardhatRuntimeEnvironment, TaskArguments } from "hardhat/types";
+
 import assert from "node:assert/strict";
 import { describe, it } from "node:test";
 
@@ -6,14 +8,17 @@ import {
   assertRejectsWithHardhatError,
   useFixtureProject,
 } from "@nomicfoundation/hardhat-test-utils";
+import { ensureError } from "@nomicfoundation/hardhat-utils/error";
+import { overrideTask } from "hardhat/config";
+import { createHardhatRuntimeEnvironment } from "hardhat/hre";
+
+import HardhatMochaPlugin from "../src/index.js";
 
 describe("Hardhat Mocha plugin", () => {
   describe("Success", () => {
     useFixtureProject("test-project");
 
     it("should work", async () => {
-      const { createHardhatRuntimeEnvironment } = await import("hardhat/hre");
-
       const hardhatConfig = await import(
         "./fixture-projects/test-project/hardhat.config.js"
       );
@@ -35,8 +40,6 @@ describe("Hardhat Mocha plugin", () => {
     useFixtureProject("invalid-mocha-config");
 
     it("should fail", async () => {
-      const { createHardhatRuntimeEnvironment } = await import("hardhat/hre");
-
       const errors =
         "\t* Config error in config.test.mocha.delay: Expected boolean, received number";
 
@@ -51,4 +54,96 @@ describe("Hardhat Mocha plugin", () => {
       );
     });
   });
+
+  describe("build invocation", () => {
+    useFixtureProject("test-project");
+
+    function buildArgCaptor() {
+      const buildArgs: any[] = [];
+      const buildOverride = overrideTask("build")
+        .setAction(async () => {
+          return {
+            default: (args: any) => {
+              buildArgs.push(args);
+              return { contractRootPaths: [], testRootPaths: [] };
+            },
+          };
+        })
+        .build();
+      return { buildArgs, buildOverride };
+    }
+
+    async function runMochaIgnoringEsmReRunErrors(
+      hre: HardhatRuntimeEnvironment,
+      args: TaskArguments = {},
+    ) {
+      try {
+        await hre.tasks.getTask(["test", "mocha"]).run(args);
+      } catch (error) {
+        ensureError(error);
+        assert.match(
+          error.message,
+          /ESM and you've programmatically run your tests twice/i,
+        );
+      }
+    }
+
+    it("should call build without noTests when splitTestsCompilation is false", async () => {
+      const { buildArgs, buildOverride } = buildArgCaptor();
+      const hre = await createHardhatRuntimeEnvironment({
+        plugins: [HardhatMochaPlugin],
+        tasks: [buildOverride],
+      });
+
+      await runMochaIgnoringEsmReRunErrors(hre);
+
+      assert.equal(buildArgs.length, 1);
+      assert.equal(buildArgs[0].noTests, false);
+    });
+
+    it("should call build with noTests when splitTestsCompilation is true", async () => {
+      const { buildArgs, buildOverride } = buildArgCaptor();
+      const hre = await createHardhatRuntimeEnvironment({
+        solidity: {
+          version: "0.8.28",
+          splitTestsCompilation: true,
+        },
+        plugins: [HardhatMochaPlugin],
+        tasks: [buildOverride],
+      });
+
+      await runMochaIgnoringEsmReRunErrors(hre);
+
+      assert.equal(buildArgs.length, 1);
+      assert.equal(buildArgs[0].noTests, true);
+    });
+
+    it("should skip compilation when noCompile is true with splitTestsCompilation", async () => {
+      const { buildArgs, buildOverride } = buildArgCaptor();
+      const hre = await createHardhatRuntimeEnvironment({
+        solidity: {
+          version: "0.8.28",
+          splitTestsCompilation: true,
+        },
+        plugins: [HardhatMochaPlugin],
+        tasks: [buildOverride],
+      });
+
+      await runMochaIgnoringEsmReRunErrors(hre, { noCompile: true });
+
+      assert.equal(buildArgs.length, 0);
+    });
+
+    it("should skip compilation when noCompile is true without splitTestsCompilation", async () => {
+      const { buildArgs, buildOverride } = buildArgCaptor();
+      const hre = await createHardhatRuntimeEnvironment({
+        plugins: [HardhatMochaPlugin],
+        tasks: [buildOverride],
+      });
+
+      await runMochaIgnoringEsmReRunErrors(hre, { noCompile: true });
+
+      assert.equal(buildArgs.length, 0);
+    });
+  });
 });