From 839f6794353a959d2ae520e840c157e642f53f26 Mon Sep 17 00:00:00 2001
From: Tryggvi Gylfason <tryggvi@spotify.com>
Date: Wed, 13 Nov 2024 17:08:22 +0100
Subject: [PATCH 1/2] jest: support custom testEnvironment

---
 packages/knip/fixtures/plugins/jest2/jest.config.js      | 2 ++
 packages/knip/fixtures/plugins/jest2/jest.environment.js | 1 +
 packages/knip/src/plugins/jest/index.ts                  | 9 ++++++++-
 packages/knip/test/plugins/jest2.test.ts                 | 7 +++++--
 4 files changed, 16 insertions(+), 3 deletions(-)
 create mode 100644 packages/knip/fixtures/plugins/jest2/jest.environment.js

diff --git a/packages/knip/fixtures/plugins/jest2/jest.config.js b/packages/knip/fixtures/plugins/jest2/jest.config.js
index cd556eaef..3669705e0 100644
--- a/packages/knip/fixtures/plugins/jest2/jest.config.js
+++ b/packages/knip/fixtures/plugins/jest2/jest.config.js
@@ -1,3 +1,5 @@
 module.exports = {
   displayName: 'dev',
+    testEnvironment:
+    '<rootDir>/jest.environment.js',
 };
diff --git a/packages/knip/fixtures/plugins/jest2/jest.environment.js b/packages/knip/fixtures/plugins/jest2/jest.environment.js
new file mode 100644
index 000000000..f053ebf79
--- /dev/null
+++ b/packages/knip/fixtures/plugins/jest2/jest.environment.js
@@ -0,0 +1 @@
+module.exports = {};
diff --git a/packages/knip/src/plugins/jest/index.ts b/packages/knip/src/plugins/jest/index.ts
index 583594ef0..f23a100d9 100644
--- a/packages/knip/src/plugins/jest/index.ts
+++ b/packages/knip/src/plugins/jest/index.ts
@@ -58,7 +58,14 @@ const resolveDependencies = async (config: JestInitialOptions, options: PluginOp
 
   const runner = config.runner ? [config.runner] : [];
   const runtime = config.runtime && config.runtime !== 'jest-circus' ? [config.runtime] : [];
-  const environments = config.testEnvironment === 'jsdom' ? ['jest-environment-jsdom'] : [];
+
+  let environments: Array<string> = [];
+  if (config.testEnvironment === 'jsdom') {
+    environments = ['jest-environment-jsdom'];
+  } else if (config.testEnvironment) {
+    environments = [config.testEnvironment];
+  }
+
   const resolvers = config.resolver ? [config.resolver] : [];
   const reporters = config.reporters
     ? config.reporters
diff --git a/packages/knip/test/plugins/jest2.test.ts b/packages/knip/test/plugins/jest2.test.ts
index 664042977..e85de0323 100644
--- a/packages/knip/test/plugins/jest2.test.ts
+++ b/packages/knip/test/plugins/jest2.test.ts
@@ -19,13 +19,16 @@ test('Find dependencies with the Jest plugin', async () => {
   // <rootDir> to reference the root directory.
   assert(!issues.files.has(join(cwd, 'project1/setupFiles/setup.js')));
 
+  // Correctly identifies a local `testEnvironment` file.
+  assert(!issues.files.has(join(cwd, 'jest.environment.js')));
+
   assert.deepEqual(counters, {
     ...baseCounters,
     files: 0,
     devDependencies: 1,
     unlisted: 0,
     unresolved: 0,
-    processed: 4,
-    total: 4,
+    processed: 5,
+    total: 5,
   });
 });

From b80e392ae1433677a9331e92c2a09837323623e1 Mon Sep 17 00:00:00 2001
From: Tryggvi Gylfason <tryggvi@spotify.com>
Date: Wed, 13 Nov 2024 20:43:41 +0100
Subject: [PATCH 2/2] resolve environments in a single expression

---
 packages/knip/src/plugins/jest/index.ts | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/knip/src/plugins/jest/index.ts b/packages/knip/src/plugins/jest/index.ts
index f23a100d9..2bfe09501 100644
--- a/packages/knip/src/plugins/jest/index.ts
+++ b/packages/knip/src/plugins/jest/index.ts
@@ -58,14 +58,12 @@ const resolveDependencies = async (config: JestInitialOptions, options: PluginOp
 
   const runner = config.runner ? [config.runner] : [];
   const runtime = config.runtime && config.runtime !== 'jest-circus' ? [config.runtime] : [];
-
-  let environments: Array<string> = [];
-  if (config.testEnvironment === 'jsdom') {
-    environments = ['jest-environment-jsdom'];
-  } else if (config.testEnvironment) {
-    environments = [config.testEnvironment];
-  }
-
+  const environments =
+    config.testEnvironment === 'jsdom'
+      ? ['jest-environment-jsdom']
+      : config.testEnvironment
+        ? [config.testEnvironment]
+        : [];
   const resolvers = config.resolver ? [config.resolver] : [];
   const reporters = config.reporters
     ? config.reporters