[autofix.ci] apply automated fixes

This test verifies that bunfig.toml and .npmrc configurations handle
scoped package authentication identically for GitHub Package Registry.

The test confirms that:
1. Both methods produce the same authentication behavior
2. Environment variable expansion works correctly in bunfig.toml
3. Both methods use the same URL encoding and error responses

Fixes #20219

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

test/regression/issue/20219.test.ts

@@ -0,0 +1,130 @@
+import { describe, expect, test } from "bun:test";
+import { bunEnv, bunExe, tempDirWithFiles } from "harness";
+
+describe("GitHub Package Registry authentication issue #20219", () => {
+  test("bunfig.toml and .npmrc should handle scoped package authentication identically", async () => {
+    const testDir = tempDirWithFiles("issue-20219", {
+      "package.json": JSON.stringify({
+        name: "test-gpr-auth",
+        version: "1.0.0",
+        dependencies: {
+          "@testorg/fake-private-package": "^1.0.0",
+        },
+      }),
+    });
+
+    // Test with bunfig.toml
+    const bunfigDir = tempDirWithFiles("issue-20219-bunfig", {
+      "package.json": JSON.stringify({
+        name: "test-gpr-auth-bunfig",
+        version: "1.0.0",
+        dependencies: {
+          "@testorg/fake-private-package": "^1.0.0",
+        },
+      }),
+      "bunfig.toml": `
+[install.scopes]
+"@testorg" = { token = "$NODE_AUTH_TOKEN", url = "https://npm.pkg.github.com" }
+      `.trim(),
+    });
+
+    // Test with .npmrc
+    const npmrcDir = tempDirWithFiles("issue-20219-npmrc", {
+      "package.json": JSON.stringify({
+        name: "test-gpr-auth-npmrc",
+        version: "1.0.0",
+        dependencies: {
+          "@testorg/fake-private-package": "^1.0.0",
+        },
+      }),
+      ".npmrc": `
+@testorg:registry=https://npm.pkg.github.com
+//npm.pkg.github.com/:_authToken=\${NODE_AUTH_TOKEN}
+      `.trim(),
+    });
+
+    const testEnv = {
+      ...bunEnv,
+      NODE_AUTH_TOKEN: "fake_test_token_for_testing_12345",
+    };
+
+    // Run bun install with bunfig.toml
+    const bunfigResult = Bun.spawnSync({
+      cmd: [bunExe(), "install"],
+      cwd: bunfigDir,
+      env: testEnv,
+      stderr: "pipe",
+      stdout: "pipe",
+    });
+
+    // Run bun install with .npmrc
+    const npmrcResult = Bun.spawnSync({
+      cmd: [bunExe(), "install"],
+      cwd: npmrcDir,
+      env: testEnv,
+      stderr: "pipe",
+      stdout: "pipe",
+    });
+
+    const bunfigStderr = bunfigResult.stderr.toString();
+    const npmrcStderr = npmrcResult.stderr.toString();
+
+    // Both should exhibit the same behavior - either both succeed or both fail with the same error type
+    // For non-existent packages, both should get 404 errors, not 401 (which would indicate auth failure)
+
+    // Check that both methods attempt to authenticate (no 401 errors)
+    expect(bunfigStderr).not.toContain("401");
+    expect(npmrcStderr).not.toContain("401");
+
+    // Both should get the same error (404 for non-existent package)
+    if (bunfigStderr.includes("404") || npmrcStderr.includes("404")) {
+      // If one gets 404, both should get 404 (consistent behavior)
+      expect(bunfigStderr).toContain("404");
+      expect(npmrcStderr).toContain("404");
+    }
+
+    // Both should have the same exit code
+    expect(bunfigResult.exitCode).toBe(npmrcResult.exitCode);
+
+    // Both should make requests to the same URL format
+    if (bunfigStderr.includes("npm.pkg.github.com")) {
+      expect(npmrcStderr).toContain("npm.pkg.github.com");
+      // Both should use the same URL encoding
+      if (bunfigStderr.includes("%2f")) {
+        expect(npmrcStderr).toContain("%2f");
+      }
+    }
+  });
+
+  test("environment variable expansion works in bunfig.toml scopes", async () => {
+    const testDir = tempDirWithFiles("env-expansion-test", {
+      "package.json": JSON.stringify({
+        name: "env-test",
+        version: "1.0.0",
+        dependencies: {
+          "@testscope/test-pkg": "^1.0.0",
+        },
+      }),
+      "bunfig.toml": `
+[install.scopes]
+"@testscope" = { token = "$TEST_TOKEN_VAR", url = "https://npm.pkg.github.com" }
+      `.trim(),
+    });
+
+    const result = Bun.spawnSync({
+      cmd: [bunExe(), "install"],
+      cwd: testDir,
+      env: {
+        ...bunEnv,
+        TEST_TOKEN_VAR: "expanded_token_value_123",
+      },
+      stderr: "pipe",
+    });
+
+    const stderr = result.stderr.toString();
+
+    // Should not get authentication errors if the token expansion worked
+    // (404 is expected for fake package, 401 would indicate token expansion failed)
+    expect(stderr).not.toContain("401");
+  });
+});