Write the Ruby environment information into a temporary file (#918)

Some shell plugins take the stderr pipe over completely and prevent the
NodeJS process from properly writing to the stderr in the shell. To
avoid being susceptible to this issue, we can write the results into a
temporary file we control

src/ruby.ts

@@ -1,5 +1,6 @@
 import path from "path";
 import fs from "fs/promises";
+import os from "os";
 
 import * as vscode from "vscode";
 
@@ -170,11 +171,19 @@ export class Ruby {
   private async activate(ruby: string) {
     let command = this.shell ? `${this.shell} -ic '` : "";
 
+    // Certain shell plugins take over standard pipes like `stderr` and cause activation issues. To get around tools
+    // that do that, we use a temporary file to write the environment information from Ruby and then read it in NodeJS
+    // to apply the right environment variables
+    const tmpFilePath = path.join(
+      os.tmpdir(),
+      `ruby_lsp_${path.basename(this.workingFolderPath)}`,
+    );
+
     // The Ruby activation script is intentionally written as an array that gets joined into a one liner because some
     // terminals cannot handle line breaks. Do not switch this to a multiline string or that will break activation for
     // those terminals
     const script = [
-      "STDERR.printf(%{RUBY_ENV_ACTIVATE%sRUBY_ENV_ACTIVATE}, ",
+      `File.write(\\"${tmpFilePath}\\", `,
       "JSON.dump({ env: ENV.to_h, ruby_version: RUBY_VERSION, yjit: defined?(RubyVM::YJIT) }))",
     ].join("");
 
@@ -188,16 +197,19 @@ export class Ruby {
       `Trying to activate Ruby environment with command: ${command} inside directory: ${this.cwd}`,
     );
 
-    const result = await asyncExec(command, { cwd: this.cwd });
-    const rubyInfoJson = /RUBY_ENV_ACTIVATE(.*)RUBY_ENV_ACTIVATE/.exec(
-      result.stderr,
-    )![1];
-
-    const rubyInfo = JSON.parse(rubyInfoJson);
+    try {
+      await asyncExec(command, { cwd: this.cwd });
+      const envJson = await fs.readFile(tmpFilePath, "utf8");
+      const rubyInfo = JSON.parse(envJson);
 
-    this._env = rubyInfo.env;
-    this.rubyVersion = rubyInfo.ruby_version;
-    this.yjitEnabled = rubyInfo.yjit === "constant";
+      this._env = rubyInfo.env;
+      this.rubyVersion = rubyInfo.ruby_version;
+      this.yjitEnabled = rubyInfo.yjit === "constant";
+    } catch (error: any) {
+      // Ensure we cleanup the temp file even if we failed to activate
+      await fs.rm(tmpFilePath);
+      throw error;
+    }
   }
 
   // Fetch information related to the Ruby version. This can only be invoked after activation, so that `rubyVersion` is