From 3f88cf10fc5f4a6339ab456936a521d7d439c274 Mon Sep 17 00:00:00 2001
From: Tomasz Godzik <tgodzik@virtuslab.com>
Date: Mon, 8 Aug 2022 17:54:04 +0200
Subject: [PATCH] feature: Try and resolve java home if it's a symlink

Resolves https://github.com/scalameta/metals-vscode/issues/1094
---
 src/__tests__/getJavaHome.test.ts | 8 ++++++++
 src/getJavaHome.ts                | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/__tests__/getJavaHome.test.ts b/src/__tests__/getJavaHome.test.ts
index 42881d5..30c89b2 100644
--- a/src/__tests__/getJavaHome.test.ts
+++ b/src/__tests__/getJavaHome.test.ts
@@ -20,6 +20,14 @@ describe("getJavaHome", () => {
     expect(javaHome).toBe(javaHomeConfig);
   });
 
+  it("infers-from-symlink", async () => {
+    if (process.platform == "linux") {
+      const javaHomeConfig = "/usr/bin/java";
+      const javaHome = await getJavaHome(javaHomeConfig);
+      expect(javaHome).not.toBe(javaHomeConfig);
+    }
+  });
+
   it("reads from JAVA_HOME", async () => {
     const JAVA_HOME = "/path/to/java";
     process.env = { ...originalEnv, JAVA_HOME };
diff --git a/src/getJavaHome.ts b/src/getJavaHome.ts
index 300a4bf..2afc25a 100644
--- a/src/getJavaHome.ts
+++ b/src/getJavaHome.ts
@@ -39,6 +39,14 @@ function fromConfig(
     typeof configuredJavaHome === "string" &&
     configuredJavaHome.trim() !== ""
   ) {
+    if (fs.existsSync(configuredJavaHome)) {
+      const stat = fs.lstatSync(configuredJavaHome);
+      const realpath = fs.realpathSync(configuredJavaHome);
+      if (stat.isSymbolicLink() && realpath.endsWith(`bin${path.sep}java`)) {
+        const javaHome = path.dirname(path.dirname(realpath));
+        return TE.right(javaHome);
+      }
+    }
     return TE.right(configuredJavaHome);
   } else {
     return TE.left({});