Fix workspace gaps: test deps, bunfig, TSX, Windows PATH

millbun/integration/resources/scalajs-bunfig/.npmrc

@@ -0,0 +1,2 @@
+# Marker .npmrc for integration test — should NOT propagate beyond install
+registry=https://registry.npmjs.org/

millbun/integration/resources/scalajs-bunfig/build.mill

@@ -0,0 +1,28 @@
+//| mill-version: 1.1.5
+//| mill-jvm-version: system
+//| mvnDeps:
+//| - com.tjclp::mill-bun_mill1:0.1.0-SNAPSHOT
+
+package build
+
+import mill.*
+import mill.scalalib.*
+import mill.scalajslib.*
+import mill.scalajslib.api.*
+import mill.scalajslib.bun.*
+
+object app extends BunScalaJSModule {
+  override def moduleDir = build.moduleDir
+  def scalaVersion = "3.8.2"
+
+  override def mainClass = Some("Main")
+  override def moduleKind = Task { ModuleKind.ESModule }
+  override def bunBundleTarget = Task { "bun" }
+
+  object test extends BunScalaJSTests, TestModule.Utest {
+    def mvnDeps = Seq(
+      mvn"com.lihaoyi::utest::0.8.5"
+    )
+    def testFramework = "utest.runner.Framework"
+  }
+}

millbun/integration/resources/scalajs-bunfig/bunfig.toml

@@ -0,0 +1,3 @@
+# Marker bunfig for integration test — verifies propagation to Scala.js workspaces
+[install]
+auto = "disable"

millbun/integration/resources/scalajs-bunfig/src/Main.scala

@@ -0,0 +1,3 @@
+object Main extends App {
+  println("Hello from scala.js bunfig")
+}

millbun/integration/resources/scalajs-bunfig/src/Words.scala

@@ -0,0 +1,3 @@
+object Words {
+  def greeting(name: String): String = s"Hello, $name!"
+}

millbun/integration/resources/scalajs-bunfig/test/src/WordsTests.scala

@@ -0,0 +1,9 @@
+import utest.*
+
+object WordsTests extends TestSuite {
+  val tests: Tests = Tests {
+    test("greeting") {
+      assert(Words.greeting("Bun") == "Hello, Bun!")
+    }
+  }
+}

millbun/integration/resources/typescript-bunfig/.npmrc

@@ -0,0 +1,2 @@
+# Marker .npmrc for integration test — should NOT propagate beyond install
+registry=https://registry.npmjs.org/

millbun/integration/resources/typescript-bunfig/app/src/main.ts

@@ -0,0 +1 @@
+console.log("Hello from Bun config propagation!");

millbun/integration/resources/typescript-bunfig/build.mill

@@ -0,0 +1,14 @@
+//| mill-version: 1.1.5
+//| mill-jvm-version: system
+//| mvnDeps:
+//| - com.tjclp::mill-bun_mill1:0.1.0-SNAPSHOT
+
+package build
+
+import mill.*
+import mill.javascriptlib.bun.*
+
+object app extends BunTypeScriptModule {
+  // Keep bunfig/.npmrc at the workspace root so the test proves explicit propagation.
+  override def moduleDir = build.moduleDir / "app"
+}

millbun/integration/resources/typescript-bunfig/bunfig.toml

@@ -0,0 +1,3 @@
+# Marker bunfig for integration test — verifies propagation to workspaces
+[install]
+auto = "disable"

millbun/integration/resources/typescript-test-deps/build.mill

@@ -0,0 +1,21 @@
+//| mill-version: 1.1.5
+//| mill-jvm-version: system
+//| mvnDeps:
+//| - com.tjclp::mill-bun_mill1:0.1.0-SNAPSHOT
+
+package build
+
+import mill.*
+import mill.javascriptlib.bun.*
+
+object app extends BunTypeScriptModule {
+  override def moduleDir = build.moduleDir
+
+  // Production dependency
+  override def npmDeps = Task { Seq("is-even@1.0.0") }
+
+  object test extends BunTypeScriptTests {
+    // Test-only dependency — should land in devDependencies, not dependencies
+    override def npmDeps = Task { Seq("is-odd@3.0.1") }
+  }
+}

millbun/integration/resources/typescript-test-deps/src/main.ts

@@ -0,0 +1,7 @@
+import isEven from "is-even";
+
+export function checkEven(n: number): boolean {
+  return isEven(n);
+}
+
+console.log(`4 is even: ${checkEven(4)}`);

millbun/integration/resources/typescript-test-deps/test/main.test.ts

@@ -0,0 +1,12 @@
+import { expect, test } from "bun:test";
+import isOdd from "is-odd";
+import { checkEven } from "../src/main";
+
+test("checkEven", () => {
+  expect(checkEven(4)).toBe(true);
+  expect(checkEven(3)).toBe(false);
+});
+
+test("test-only dep is available", () => {
+  expect(isOdd(3)).toBe(true);
+});

millbun/integration/resources/typescript-tsx/build.mill

@@ -0,0 +1,14 @@
+//| mill-version: 1.1.5
+//| mill-jvm-version: system
+//| mvnDeps:
+//| - com.tjclp::mill-bun_mill1:0.1.0-SNAPSHOT
+
+package build
+
+import mill.*
+import mill.javascriptlib.bun.*
+
+object app extends BunTypeScriptModule {
+  override def moduleDir = build.moduleDir
+  override def bunBundleTarget = Task { "bun" }
+}

millbun/integration/resources/typescript-tsx/src/helper.ts

@@ -0,0 +1,3 @@
+export function label(framework: string): string {
+  return `Hello from ${framework}`;
+}

millbun/integration/resources/typescript-tsx/src/main.tsx

@@ -0,0 +1,4 @@
+// TSX entrypoint — verifies .tsx fallback resolution works with Bun's native JSX.
+import { label } from "./helper";
+
+console.log(label("TSX"));

millbun/integration/src/mill/bun/BunScalaJSIntegrationTests.scala

@@ -95,5 +95,34 @@ object BunScalaJSIntegrationTests extends TestSuite {
       val res = tester.eval("app.test.bunTest")
       assert(res.isSuccess)
     }
+
+    test("bunfig propagates to Scala.js workspaces without leaking .npmrc") {
+      val tester = this.tester("scalajs-bunfig")
+
+      val installRes = tester.eval("app.bunInstall")
+      assert(installRes.isSuccess)
+      val installDir = tester.workspacePath / "out" / "app" / "bunInstall.dest"
+      assert(os.exists(installDir / ".npmrc"))
+      assert(os.exists(installDir / "bunfig.toml"))
+
+      val linkRes = tester.eval("app.fastLinkJS")
+      assert(linkRes.isSuccess)
+      val linkedDir = tester.workspacePath / "out" / "app" / "fastLinkJS.dest"
+      assert(os.exists(linkedDir / "bunfig.toml"))
+      assert(!os.exists(linkedDir / ".npmrc"))
+
+      val compileRes = tester.eval("app.bunCompileExecutable")
+      assert(compileRes.isSuccess)
+      val compileWorkspace = tester.workspacePath / "out" / "app" / "bunCompileExecutable.dest" / "workspace"
+      assert(os.exists(compileWorkspace / "bunfig.toml"))
+      assert(!os.exists(compileWorkspace / ".npmrc"))
+
+      val testRes = tester.eval("app.test.bunTest")
+      assert(testRes.isSuccess)
+      val testRoot = tester.workspacePath / "out" / "app" / "test"
+      assert(os.exists(testRoot))
+      assert(os.walk(testRoot).exists(_.last == "bunfig.toml"))
+      assert(!os.walk(testRoot).exists(_.last == ".npmrc"))
+    }
   }
 }

millbun/integration/src/mill/bun/BunTypeScriptIntegrationTests.scala

@@ -123,6 +123,56 @@ object BunTypeScriptIntegrationTests extends TestSuite {
       assert(betaRun.out.text().trim == "Beta worker")
     }
 
+    test("tsx entrypoint fallback") {
+      val tester = this.tester("typescript-tsx")
+      val res = tester.eval("app.run")
+      assert(res.isSuccess)
+
+      val log = os.read(commandLogPath(tester, "app.run")).trim
+      assert(log.contains("Hello from TSX"))
+    }
+
+    test("bunfig propagates to compile workspace without leaking .npmrc") {
+      val tester = this.tester("typescript-bunfig")
+      val res = tester.eval("app.compile")
+      assert(res.isSuccess)
+
+      val installDir = tester.workspacePath / "out" / "app" / "npmInstall.dest"
+      val compileDir = tester.workspacePath / "out" / "app" / "compile.dest"
+
+      // Install workspace keeps both configs.
+      assert(os.exists(installDir / ".npmrc"))
+      assert(os.exists(installDir / "bunfig.toml"))
+      // Compile workspace should only get bunfig.
+      assert(os.exists(compileDir / "bunfig.toml"))
+      assert(!os.exists(compileDir / ".npmrc"))
+    }
+
+    test("test deps are devDependencies") {
+      val tester = this.tester("typescript-test-deps")
+
+      // Outer module should have is-even in dependencies
+      val outerRes = tester.eval("app.npmInstall")
+      assert(outerRes.isSuccess)
+      val outerPkg = ujson.read(os.read(tester.workspacePath / "out" / "app" / "npmInstall.dest" / "package.json"))
+      assert(outerPkg("dependencies").obj.contains("is-even"))
+      assert(!outerPkg("dependencies").obj.contains("is-odd"))
+
+      // Test module should have is-odd in devDependencies (not dependencies)
+      val testRes = tester.eval("app.test.npmInstall")
+      assert(testRes.isSuccess)
+      val testPkg = ujson.read(os.read(tester.workspacePath / "out" / "app" / "test" / "npmInstall.dest" / "package.json"))
+      assert(testPkg("devDependencies").obj.contains("is-odd"))
+      assert(!testPkg("dependencies").obj.contains("is-odd"))
+      assert(!testPkg("devDependencies").obj.contains("is-even"))
+      // Outer deps should also be present
+      assert(testPkg("dependencies").obj.contains("is-even"))
+
+      // Tests should actually run (both deps available)
+      val runRes = tester.eval("app.test.test")
+      assert(runRes.isSuccess)
+    }
+
     test("bunEnv") {
       val tester = this.tester("typescript-env")
       val res = tester.eval("app.bundle")

millbun/src/mill/bun/BunToolchainModule.scala

@@ -16,11 +16,21 @@ object BunToolchainModule {
       (parts(0), ujson.Str(parts.lift(1).getOrElse("")))
   }
 
-  /** Resolve an executable name from PATH. */
+  /** Build candidate executable names from a base name and PATHEXT extensions.
+   *  PATHEXT is Windows-specific and always semicolon-delimited regardless of platform. */
+  def executableCandidates(name: String, pathExt: String): Seq[String] = {
+    val extensions = pathExt.split(";").filter(_.nonEmpty)
+    if (extensions.nonEmpty) Seq(name) ++ extensions.map(ext => name + ext.toLowerCase)
+    else Seq(name)
+  }
+
+  /** Resolve an executable name from PATH, respecting PATHEXT on Windows. */
   def findOnPath(name: String): Option[os.Path] = {
     val pathDirs = sys.env.getOrElse("PATH", "").split(java.io.File.pathSeparator)
+    val candidates = executableCandidates(name, sys.env.getOrElse("PATHEXT", ""))
+
     pathDirs.iterator
-      .map(dir => os.Path(dir) / name)
+      .flatMap(dir => candidates.iterator.map(c => os.Path(dir) / c))
       .find(os.exists(_))
   }
 
@@ -88,8 +98,11 @@ trait BunToolchainModule extends Module {
    *
    * Bun works without a bunfig, but copying root configs makes the generated
    * task workspaces closer to the source workspace.
+   *
+   * Declared as Task.Input so Mill's sandbox checker allows reading from the
+   * workspace root and re-evaluates when the files change.
    */
-  def bunfigFiles: T[Seq[PathRef]] = Task {
+  def bunfigFiles: T[Seq[PathRef]] = Task.Input {
     Seq(BuildCtx.workspaceRoot / "bunfig.toml", BuildCtx.workspaceRoot / ".bunfig.toml")
       .filter(os.exists)
       .map(PathRef(_))