1 files changed, 61 insertions, 0 deletions

diff --git a/packages/turbo-ignore/__tests__/getComparison.test.ts b/packages/turbo-ignore/__tests__/getComparison.test.ts
new file mode 100644
index 0000000..b5c74c7
--- /dev/null
+++ b/packages/turbo-ignore/__tests__/getComparison.test.ts
@@ -0,0 +1,61 @@
+import { getComparison } from "../src/getComparison";
+import { spyConsole, mockEnv } from "@turbo/test-utils";
+
+describe("getComparison()", () => {
+  mockEnv();
+  const mockConsole = spyConsole();
+  it("uses headRelative comparison when not running Vercel CI", async () => {
+    expect(getComparison({ workspace: "test-workspace" }))
+      .toMatchInlineSnapshot(`
+        Object {
+          "ref": "HEAD^",
+          "type": "headRelative",
+        }
+      `);
+  });
+
+  it("returns null when running in Vercel CI with no VERCEL_GIT_PREVIOUS_SHA", async () => {
+    process.env.VERCEL = "1";
+    process.env.VERCEL_GIT_COMMIT_REF = "my-branch";
+    expect(getComparison({ workspace: "test-workspace" })).toBeNull();
+    expect(mockConsole.log).toHaveBeenCalledWith(
+      "≫  ",
+      'No previous deployments found for "test-workspace" on branch "my-branch".'
+    );
+  });
+
+  it("uses custom fallback when running in Vercel CI with no VERCEL_GIT_PREVIOUS_SHA", async () => {
+    process.env.VERCEL = "1";
+    process.env.VERCEL_GIT_COMMIT_REF = "my-branch";
+    expect(getComparison({ workspace: "test-workspace", fallback: "HEAD^2" }))
+      .toMatchInlineSnapshot(`
+        Object {
+          "ref": "HEAD^2",
+          "type": "customFallback",
+        }
+      `);
+    expect(mockConsole.log).toHaveBeenNthCalledWith(
+      1,
+      "≫  ",
+      'No previous deployments found for "test-workspace" on branch "my-branch".'
+    );
+    expect(mockConsole.log).toHaveBeenNthCalledWith(
+      2,
+      "≫  ",
+      "Falling back to ref HEAD^2"
+    );
+  });
+
+  it("uses previousDeploy when running in Vercel CI with VERCEL_GIT_PREVIOUS_SHA", async () => {
+    process.env.VERCEL = "1";
+    process.env.VERCEL_GIT_PREVIOUS_SHA = "mygitsha";
+    process.env.VERCEL_GIT_COMMIT_REF = "my-branch";
+    expect(getComparison({ workspace: "test-workspace" }))
+      .toMatchInlineSnapshot(`
+        Object {
+          "ref": "mygitsha",
+          "type": "previousDeploy",
+        }
+      `);
+  });
+});