Encapsulate detekt-gradle JAVA_HOME logic (#411)

Ensure we use our hermetic install of Java for detekt-gradle tests,
without having to specify it at the workflow level. Tested successfully
in the cross-repo workflow.

Author: TylerJang27

linters/detekt/detekt.test.ts

@@ -2,7 +2,7 @@ import * as fs from "fs";
 import path from "path";
 import { customLinterCheckTest, linterCheckTest, TestCallback } from "tests";
 import { TrunkLintDriver } from "tests/driver";
-import { osTimeoutMultiplier, skipOS, TEST_DATA } from "tests/utils";
+import { DOWNLOAD_CACHE, osTimeoutMultiplier, recurseLevels, skipOS, TEST_DATA } from "tests/utils";
 
 // detekt tests can sometimes take a while.
 jest.setTimeout(300000 * osTimeoutMultiplier); // 300s or 900s
@@ -38,6 +38,23 @@ const gradlePreCheck: TestCallback = (driver) => {
   fs.readdirSync(path.resolve(driver.getSandbox(), TEST_DATA, "detekt_gradle")).forEach((file) => {
     driver.moveFile(path.join(TEST_DATA, "detekt_gradle", file), file);
   });
+
+  const trunkYamlPath = ".trunk/trunk.yaml";
+  const currentContents = driver.readFile(trunkYamlPath);
+  const newContents = currentContents.concat(`  definitions:
+    - name: detekt-gradle
+      runtime: java
+`);
+  driver.writeFile(trunkYamlPath, newContents);
+
+  driver.runTrunkSync(["install"]);
+  const javaPath = recurseLevels(path.resolve(DOWNLOAD_CACHE, "jdk-13"), 1);
+  const finalContents = newContents.concat(`      environment:
+        - name: JAVA_HOME
+          value: ${javaPath}
+          optional: false
+`);
+  driver.writeFile(trunkYamlPath, finalContents);
   // trunk-ignore-end(semgrep)
 };
 

tests/driver/driver.ts

@@ -5,15 +5,13 @@ import * as os from "os";
 import path from "path";
 import * as git from "simple-git";
 import { SetupSettings } from "tests/driver";
-import { ARGS, REPO_ROOT, TEST_DATA } from "tests/utils";
+import { ARGS, DOWNLOAD_CACHE, REPO_ROOT, TEMP_PREFIX, TEST_DATA } from "tests/utils";
 import { getTrunkConfig, newTrunkYamlContents } from "tests/utils/trunk_config";
 import * as util from "util";
 import YAML from "yaml";
 
 const execFilePromise = util.promisify(execFile);
 
-const TEMP_PREFIX = "plugins_";
-
 const TEMP_SUBDIR = "tmp";
 
 const UNINITIALIZED_ERROR = `You have attempted to modify the sandbox before it was created.
@@ -25,10 +23,7 @@ export const executionEnv = (sandbox: string) => {
   return {
     ...strippedEnv,
     // This keeps test downloads separate from manual trunk invocations
-    TRUNK_DOWNLOAD_CACHE: path.resolve(
-      fs.realpathSync(os.tmpdir()),
-      `${TEMP_PREFIX}testing_download_cache`,
-    ),
+    TRUNK_DOWNLOAD_CACHE: DOWNLOAD_CACHE,
     // This is necessary to prevent launcher collision of non-atomic operations
     TMPDIR: path.resolve(sandbox, TEMP_SUBDIR),
   };

tests/utils/index.ts

@@ -1,11 +1,17 @@
 import Debug from "debug";
 import fs from "fs";
+import * as os from "os";
 import path from "path";
 import semver from "semver";
 import { CheckType, LandingState, LinterVersion, TaskFailure, TestingArguments } from "tests/types";
 
 export const REPO_ROOT = path.resolve(__dirname, "../..");
 export const TEST_DATA = "test_data";
+export const TEMP_PREFIX = "plugins_";
+export const DOWNLOAD_CACHE = path.resolve(
+  fs.realpathSync(os.tmpdir()),
+  `${TEMP_PREFIX}testing_download_cache`,
+);
 
 // As this file and folder increase in complexity, extract out functionality into other categories.
 // Avoid overpolluting a `utils` folder.
@@ -218,6 +224,24 @@ export const getVersionsForTest = (
   return [undefined];
 };
 
+/**
+ * Helper function to step N directories into a path. Throws if unavailable
+ */
+export const recurseLevels = (starterPath: string, n: number) => {
+  let currentPath = starterPath;
+  for (let i = 0; i < n; i++) {
+    const contents = fs.readdirSync(currentPath);
+    for (const file of contents) {
+      if (fs.lstatSync(path.resolve(currentPath, file)).isDirectory()) {
+        currentPath = path.resolve(currentPath, file);
+        break;
+      }
+      throw new Error(`Could not find directory inside of ${currentPath}`);
+    }
+  }
+  return currentPath;
+};
+
 /**
  * Helper callback that skips a test if the OS is included in excludedOS.
  * Intended to be passed to `skipTestIf`.