From f67d2984c3c3f26497842a04d5166707587c1fca Mon Sep 17 00:00:00 2001
From: Milos Djermanovic <milos.djermanovic@gmail.com>
Date: Mon, 29 May 2023 20:48:12 +0200
Subject: [PATCH] test: Add `FlatESLint` tests with missing config files
 (#17164)

* test: Add `FlatESLint` tests with missing config files

* assert ENOENT
---
 tests/lib/eslint/flat-eslint.js | 62 +++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/tests/lib/eslint/flat-eslint.js b/tests/lib/eslint/flat-eslint.js
index 2e23e4db2cd..24c3ab5a6c9 100644
--- a/tests/lib/eslint/flat-eslint.js
+++ b/tests/lib/eslint/flat-eslint.js
@@ -682,6 +682,37 @@ describe("FlatESLint", () => {
             );
         });
 
+        it("should throw if eslint.config.js file is not present", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath("..")
+            });
+            await assert.rejects(() => eslint.lintText("var foo = 'bar';"), /Could not find config file/u);
+        });
+
+        it("should not throw if eslint.config.js file is not present and overrideConfigFile is `true`", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(".."),
+                overrideConfigFile: true
+            });
+            await eslint.lintText("var foo = 'bar';");
+        });
+
+        it("should not throw if eslint.config.js file is not present and overrideConfigFile is path to a config file", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(".."),
+                overrideConfigFile: "fixtures/configurations/quotes-error.js"
+            });
+            await eslint.lintText("var foo = 'bar';");
+        });
+
+        it("should throw if overrideConfigFile is path to a file that doesn't exist", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(""),
+                overrideConfigFile: "does-not-exist.js"
+            });
+            await assert.rejects(() => eslint.lintText("var foo = 'bar';"), { code: "ENOENT" });
+        });
+
         it("should throw if non-string value is given to 'code' parameter", async () => {
             eslint = new FlatESLint();
             await assert.rejects(() => eslint.lintText(100), /'code' must be a string/u);
@@ -797,6 +828,37 @@ describe("FlatESLint", () => {
             assert.strictEqual(results[0].suppressedMessages.length, 0);
         });
 
+        it("should throw if eslint.config.js file is not present", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath("..")
+            });
+            await assert.rejects(() => eslint.lintFiles("fixtures/undef*.js"), /Could not find config file/u);
+        });
+
+        it("should not throw if eslint.config.js file is not present and overrideConfigFile is `true`", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(".."),
+                overrideConfigFile: true
+            });
+            await eslint.lintFiles("fixtures/undef*.js");
+        });
+
+        it("should not throw if eslint.config.js file is not present and overrideConfigFile is path to a config file", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(".."),
+                overrideConfigFile: "fixtures/configurations/quotes-error.js"
+            });
+            await eslint.lintFiles("fixtures/undef*.js");
+        });
+
+        it("should throw if overrideConfigFile is path to a file that doesn't exist", async () => {
+            eslint = new FlatESLint({
+                cwd: getFixturePath(),
+                overrideConfigFile: "does-not-exist.js"
+            });
+            await assert.rejects(() => eslint.lintFiles("undef*.js"), { code: "ENOENT" });
+        });
+
         it("should throw an error when given a config file and a valid file and invalid parser", async () => {
             eslint = new FlatESLint({
                 overrideConfig: {