Fix and test check for MSVC setup.

__tests__/msvc.test.ts

@@ -0,0 +1,36 @@
+import * as path from 'path'
+import {expect, test} from '@jest/globals'
+import {needsWindowsEnvironmentSetup} from '../src/msvc'
+import {VERSION_DEV, VERSION_LATEST} from '../src/constants'
+
+process.env['RUNNER_TOOL_CACHE'] = path.join(__dirname, 'TOOL_CACHE')
+process.env['RUNNER_TEMP'] = path.join(__dirname, 'TEMP')
+
+test('decide whether Window env must be set up for GraalVM for JDK', async () => {
+  for (var javaVersion of [
+    '17',
+    '17.0.8',
+    '17.0',
+    '21',
+    '22',
+    '22-ea',
+    '23-ea',
+    VERSION_DEV
+  ]) {
+    expect(needsWindowsEnvironmentSetup(javaVersion, '', true)).toBe(false)
+  }
+})
+
+test('decide whether Window env must be set up for legacy GraalVM', async () => {
+  for (var combination of [
+    ['7', '22.3.0'],
+    ['17', '22.3'],
+    ['7', '22.3'],
+    ['7', VERSION_DEV],
+    ['17', VERSION_LATEST]
+  ]) {
+    expect(
+      needsWindowsEnvironmentSetup(combination[0], combination[1], false)
+    ).toBe(combination[1] !== VERSION_DEV)
+  }
+})

src/msvc.ts

@@ -28,15 +28,32 @@ function findVcvarsallPath(): string {
   throw new Error('Failed to find vcvarsall.bat')
 }
 
+export function needsWindowsEnvironmentSetup(
+  javaVersion: string,
+  graalVMVersion: string,
+  isGraalVMforJDK17OrLater: boolean
+): boolean {
+  if (javaVersion === VERSION_DEV || graalVMVersion === VERSION_DEV) {
+    return false // no longer required in dev builds
+  } else if (isGraalVMforJDK17OrLater) {
+    return false // no longer required in GraalVM for JDK 17 and later.
+  }
+  return true
+}
+
 export function setUpWindowsEnvironment(
   javaVersion: string,
   graalVMVersion: string,
   isGraalVMforJDK17OrLater: boolean
 ): void {
-  if (javaVersion === javaVersion || graalVMVersion === VERSION_DEV) {
-    return // no longer required in dev builds
-  } else if (isGraalVMforJDK17OrLater) {
-    return // no longer required in GraalVM for JDK 17 and later.
+  if (
+    !needsWindowsEnvironmentSetup(
+      javaVersion,
+      graalVMVersion,
+      isGraalVMforJDK17OrLater
+    )
+  ) {
+    return
   }
 
   core.startGroup('Updating Windows environment...')