From 4e126ad7b33a287604c6c941d526a6306b22330a Mon Sep 17 00:00:00 2001
From: Josh Goldberg <josh@codecademy.com>
Date: Fri, 20 Nov 2020 20:32:47 -0500
Subject: [PATCH] Added explicit error for TSLint not being found

---
 src/input/findTSLintConfiguration.ts      |  7 +++++++
 src/input/findTslintConfiguration.test.ts | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/input/findTSLintConfiguration.ts b/src/input/findTSLintConfiguration.ts
index 24e3d52a9..b39240f50 100644
--- a/src/input/findTSLintConfiguration.ts
+++ b/src/input/findTSLintConfiguration.ts
@@ -19,6 +19,13 @@ export type FindTSLintConfigurationDependencies = {
 };
 
 const knownErrors = [
+    [
+        "command not found",
+        () =>
+            new Error(
+                "The 'tslint' command was not found. Either install it globally or add it as a devDependency of this repository.",
+            ),
+    ],
     [
         "unknown option `--print-config",
         () => new Error("TSLint v5.18 required. Please update your version."),
diff --git a/src/input/findTslintConfiguration.test.ts b/src/input/findTslintConfiguration.test.ts
index cf0e9b4f9..fd6958614 100644
--- a/src/input/findTslintConfiguration.test.ts
+++ b/src/input/findTslintConfiguration.test.ts
@@ -49,6 +49,25 @@ describe("findTSLintConfiguration", () => {
         );
     });
 
+    it("replaces an error with a v5.18 request when the tslint command is not found", async () => {
+        // Arrange
+        const stderr = "/bin/sh tslint: command not found";
+        const dependencies = createStubDependencies({
+            exec: createStubThrowingExec({ stderr }),
+        });
+
+        // Act
+        const result = await findTSLintConfiguration(dependencies, undefined);
+
+        // Assert
+        expect(result).toEqual(
+            expect.objectContaining({
+                message:
+                    "The 'tslint' command was not found. Either install it globally or add it as a devDependency of this repository.",
+            }),
+        );
+    });
+
     it("replaces an error with a v5.18 request when the --print-config option is unsupported", async () => {
         // Arrange
         const stderr = "unknown option `--print-config";