Test: add edge case coverage for template upload and preview routes

tests/test_template_file_routes.py

@@ -0,0 +1,71 @@
+from fastapi.testclient import TestClient
+from api.main import app
+
+client = TestClient(app)
+
+
+def test_upload_template_pdf():
+    pdf_content = b"%PDF-1.4 test pdf content"
+
+    files = {
+        "file": ("sample_test.pdf", pdf_content, "application/pdf")
+    }
+
+    data = {
+        "directory": "src/inputs"
+    }
+
+    response = client.post(
+        "/templates/upload",
+        files=files,
+        data=data
+    )
+
+    assert response.status_code == 200
+
+    response_data = response.json()
+
+    assert "filename" in response_data
+    assert "pdf_path" in response_data
+    assert response_data["filename"].endswith(".pdf")
+
+
+def test_preview_template_pdf():
+    response = client.get(
+        "/templates/preview",
+        params={"path": "src/inputs/file.pdf"}
+    )
+
+    assert response.status_code == 200
+    assert response.headers["content-type"] == "application/pdf"
+
+def test_upload_non_pdf_should_fail():
+    files = {
+        "file": ("sample.txt", b"not a pdf", "text/plain")
+    }
+
+    response = client.post(
+        "/templates/upload",
+        files=files,
+        data={"directory": "src/inputs"}
+    )
+
+    assert response.status_code == 400
+
+
+def test_preview_missing_file_should_fail():
+    response = client.get(
+        "/templates/preview",
+        params={"path": "src/inputs/does_not_exist.pdf"}
+    )
+
+    assert response.status_code == 404
+
+
+def test_preview_outside_project_should_fail():
+    response = client.get(
+        "/templates/preview",
+        params={"path": "/etc/passwd"}
+    )
+
+    assert response.status_code == 400