Create toolchains.xml dynamically based on envs (#150)

Different runners have different JDKs installed, so using a hard-coded
list for
`toolchains.xml` doesn't work. With this change, the file is generated
based on the available `JAVA_HOME_*` environment variables.

Fixes #89 

Thanks @hfhbd for the contribution!

Co-authored-by: hfhbd <22521688+hfhbd@users.noreply.github.com>

sources/src/caching/gradle-user-home-cache.ts

@@ -7,8 +7,9 @@ import fs from 'fs'
 import {generateCacheKey} from './cache-key'
 import {CacheListener} from './cache-reporting'
 import {saveCache, restoreCache, cacheDebug, isCacheDebuggingEnabled, tryDelete} from './cache-utils'
-import {GradleHomeEntryExtractor, ConfigurationCacheEntryExtractor} from './gradle-home-extry-extractor'
 import {CacheConfig} from '../configuration'
+import {GradleHomeEntryExtractor, ConfigurationCacheEntryExtractor} from './gradle-home-extry-extractor'
+import {getPredefinedToolchains, readResourceFileAsString} from './gradle-user-home-utils'
 
 const RESTORED_CACHE_KEY_KEY = 'restored-cache-key'
 
@@ -211,14 +212,16 @@ export class GradleUserHomeCache {
             'gradle-actions.inject-develocity.init.gradle'
         ]
         for (const initScriptFilename of initScriptFilenames) {
-            const initScriptContent = this.readResourceFileAsString('init-scripts', initScriptFilename)
+            const initScriptContent = readResourceFileAsString('init-scripts', initScriptFilename)
             const initScriptPath = path.resolve(initScriptsDir, initScriptFilename)
             fs.writeFileSync(initScriptPath, initScriptContent)
         }
     }
 
     private registerToolchains(): void {
-        const preInstalledToolchains = this.readResourceFileAsString('toolchains.xml')
+        const preInstalledToolchains: string | null = getPredefinedToolchains()
+        if (preInstalledToolchains == null) return
+
         const m2dir = path.resolve(this.userHome, '.m2')
         const toolchainXmlTarget = path.resolve(m2dir, 'toolchains.xml')
         if (!fs.existsSync(toolchainXmlTarget)) {
@@ -238,13 +241,6 @@ export class GradleUserHomeCache {
         }
     }
 
-    // TODO:DAZ Move this to a utility class
-    private readResourceFileAsString(...paths: string[]): string {
-        // Resolving relative to __dirname will allow node to find the resource at runtime
-        const absolutePath = path.resolve(__dirname, '..', '..', '..', 'sources', 'src', 'resources', ...paths)
-        return fs.readFileSync(absolutePath, 'utf8')
-    }
-
     /**
      * When the GitHub environment ACTIONS_RUNNER_DEBUG is true, run Gradle with --info and --stacktrace.
      * see https://docs.github.com/en/actions/monitoring-and-troubleshooting-workflows/enabling-debug-logging

sources/src/caching/gradle-user-home-utils.ts

@@ -0,0 +1,44 @@
+import path from 'path'
+import fs from 'fs'
+
+export function readResourceFileAsString(...paths: string[]): string {
+    // Resolving relative to __dirname will allow node to find the resource at runtime
+    const absolutePath = path.resolve(__dirname, '..', '..', '..', 'sources', 'src', 'resources', ...paths)
+    return fs.readFileSync(absolutePath, 'utf8')
+}
+
+/**
+ * Iterate over all `JAVA_HOME_{version}_{arch}` envs and construct the toolchain.xml.
+ *
+ * @VisibleForTesting
+ */
+export function getPredefinedToolchains(): string | null {
+    const javaHomeEnvs: string[] = []
+    for (const javaHomeEnvsKey in process.env) {
+        if (javaHomeEnvsKey.startsWith('JAVA_HOME_')) {
+            javaHomeEnvs.push(javaHomeEnvsKey)
+        }
+    }
+    if (javaHomeEnvs.length === 0) {
+        return null
+    }
+    // language=XML
+    let toolchainsXml = `<?xml version="1.0" encoding="UTF-8"?>
+<toolchains>
+<!-- JDK Toolchains installed by default on GitHub-hosted runners -->
+`
+    for (const javaHomeEnv of javaHomeEnvs) {
+        const version = javaHomeEnv.match(/JAVA_HOME_(\d+)_/)?.[1]!
+        toolchainsXml += `  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>${version}</version>
+    </provides>
+    <configuration>
+      <jdkHome>\${env.${javaHomeEnv}}</jdkHome>
+    </configuration>
+  </toolchain>\n`
+    }
+    toolchainsXml += `</toolchains>\n`
+    return toolchainsXml
+}

sources/test/jest/predefined-toolchains.test.ts

@@ -0,0 +1,65 @@
+import {getPredefinedToolchains} from "../../src/caching/gradle-user-home-utils";
+
+describe('predefined-toolchains', () => {
+    const OLD_ENV = process.env
+    afterAll(() => {
+        process.env = OLD_ENV
+    });
+
+    describe('returns', () => {
+        it('null if no JAVA_HOME_ envs are set', async () => {
+            jest.resetModules()
+            process.env = {
+                "JAVA_HOME": "/jdks/foo_8"
+            }
+
+            const predefinedToolchains = getPredefinedToolchains()
+            expect(predefinedToolchains).toBe(null)
+        })
+        it('valid toolchains.xml if JAVA_HOME_ envs are set', async () => {
+            jest.resetModules()
+            process.env = {
+                "JAVA_HOME": "/jdks/foo_8",
+                "JAVA_HOME_8_X64": "/jdks/foo_8",
+                "JAVA_HOME_11_X64": "/jdks/foo_11",
+                "JAVA_HOME_21_ARM64": "/jdks/foo_21",
+            }
+
+            const predefinedToolchains = getPredefinedToolchains()
+            expect(predefinedToolchains).toBe(
+                // language=XML
+`<?xml version="1.0" encoding="UTF-8"?>
+<toolchains>
+<!-- JDK Toolchains installed by default on GitHub-hosted runners -->
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>8</version>
+    </provides>
+    <configuration>
+      <jdkHome>\${env.JAVA_HOME_8_X64}</jdkHome>
+    </configuration>
+  </toolchain>
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>11</version>
+    </provides>
+    <configuration>
+      <jdkHome>\${env.JAVA_HOME_11_X64}</jdkHome>
+    </configuration>
+  </toolchain>
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>21</version>
+    </provides>
+    <configuration>
+      <jdkHome>\${env.JAVA_HOME_21_ARM64}</jdkHome>
+    </configuration>
+  </toolchain>
+</toolchains>
+`)
+        })
+    })
+})