From 98fb46965b1f4a286fa4c5d3ffe802a7094c7990 Mon Sep 17 00:00:00 2001
From: Mateus Latrova <mateus.latrova@gscap.com.br>
Date: Thu, 28 Sep 2023 20:28:32 -0300
Subject: [PATCH] add test for "compare_modules" function

---
 tests/_data/empty.txt   |  0
 tests/_data/imports.txt |  3 +++
 tests/test_pipreqs.py   | 20 ++++++++++++++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 tests/_data/empty.txt
 create mode 100644 tests/_data/imports.txt

diff --git a/tests/_data/empty.txt b/tests/_data/empty.txt
new file mode 100644
index 0000000..e69de29
diff --git a/tests/_data/imports.txt b/tests/_data/imports.txt
new file mode 100644
index 0000000..32eea8a
--- /dev/null
+++ b/tests/_data/imports.txt
@@ -0,0 +1,3 @@
+pandas==2.0.0
+numpy>=1.2.3
+torch<4.0.0
\ No newline at end of file
diff --git a/tests/test_pipreqs.py b/tests/test_pipreqs.py
index 039d4fd..f1c6751 100644
--- a/tests/test_pipreqs.py
+++ b/tests/test_pipreqs.py
@@ -39,6 +39,9 @@ def setUp(self):
         self.project = os.path.join(os.path.dirname(__file__), "_data")
         self.project_clean = os.path.join(os.path.dirname(__file__), "_data_clean")
         self.project_invalid = os.path.join(os.path.dirname(__file__), "_invalid_data")
+        self.parsed_packages = [{'name': 'pandas', 'version': '2.0.0'}, {'name': 'numpy', 'version': '1.2.3'}, {'name': 'torch', 'version': '4.0.0'}]
+        self.empty_filepath = os.path.join(self.project, "empty.txt")
+        self.imports_filepath = os.path.join(self.project, "imports.txt")
         self.project_with_ignore_directory = os.path.join(
             os.path.dirname(__file__), "_data_ignore"
         )
@@ -427,6 +430,23 @@ def test_clean_with_imports_to_clean(self):
             data = f.read().lower()
             self.assertTrue(cleaned_module not in data)
 
+    def test_compare_modules(self):
+        test_cases = [
+            ( self.empty_filepath, [], set() ), # both empty
+            ( self.empty_filepath, self.parsed_packages, set() ), # only file empty
+            ( self.imports_filepath, [], set(package["name"] for package in self.parsed_packages) ), # only imports empty
+            ( self.imports_filepath, self.parsed_packages, set() ), # no difference
+            ( self.imports_filepath, self.parsed_packages[1:], set([self.parsed_packages[0]["name"]]) ) # common case
+        ]
+
+        for test_case in test_cases:
+            with self.subTest(test_case):
+                filename, imports, expected_modules_not_imported = test_case
+
+                modules_not_imported = pipreqs.compare_modules(filename, imports)
+
+                self.assertSetEqual(modules_not_imported, expected_modules_not_imported)
+
     def tearDown(self):
         """
         Remove requiremnts.txt files that were written