add new external diff __main__ module unit tests

Author: chrissimpkins

tests/test_main_unix_only.py

@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+
+import os
+import sys
+
+import pytest
+
+from fdiff.__main__ import run
+
+ROBOTO_BEFORE_PATH = os.path.join("tests", "testfiles", "Roboto-Regular.subset1.ttf")
+ROBOTO_AFTER_PATH = os.path.join("tests", "testfiles", "Roboto-Regular.subset2.ttf")
+ROBOTO_EXTDIFF_EXPECTED_PATH = os.path.join("tests", "testfiles", "roboto_extdiff_expected.txt")
+ROBOTO_EXTDIFF_COLOR_EXPECTED_PATH = os.path.join("tests", "testfiles", "roboto_extdiff_color_expected.txt")
+
+ROBOTO_BEFORE_URL = "https://github.com/source-foundry/fdiff/raw/master/tests/testfiles/Roboto-Regular.subset1.ttf"
+ROBOTO_AFTER_URL = "https://github.com/source-foundry/fdiff/raw/master/tests/testfiles/Roboto-Regular.subset2.ttf"
+
+
+# Setup: define the expected diff text for unified diff
+with open(ROBOTO_EXTDIFF_EXPECTED_PATH, "r") as robo_extdiff:
+    ROBOTO_EXTDIFF_EXPECTED = robo_extdiff.read()
+
+# Setup: define the expected diff text for unified color diff
+with open(ROBOTO_EXTDIFF_COLOR_EXPECTED_PATH, "r") as robo_extdiff_color:
+    ROBOTO_EXTDIFF_COLOR_EXPECTED = robo_extdiff_color.read()
+
+
+# # these tests rely on a PATH install of `diff` executable on Unix
+# # they are not executed on Windows platforms
+if sys.platform.startswith("win"):
+    pytest.skip("skipping windows-only tests", allow_module_level=True)
+
+
+def test_main_external_diff_default(capsys):
+    args = ["--external", "diff -u", ROBOTO_BEFORE_PATH, ROBOTO_AFTER_PATH]
+    expected_string_list = ROBOTO_EXTDIFF_EXPECTED.split("\n")
+
+    with pytest.raises(SystemExit):
+        run(args)
+
+    captured = capsys.readouterr()
+    res_string_list = captured.out.split("\n")
+    for x, line in enumerate(res_string_list):
+        # treat top two lines of the diff as comparison of first 3 chars only
+        if x in (0, 1):
+            assert line[0:2] == expected_string_list[x][0:2]
+        elif x in range(2, 10):
+            assert line == expected_string_list[x]
+        else:
+            # skip lines beyond first 10
+            pass
+
+
+def test_main_external_diff_remote(capsys):
+    args = ["--external", "diff -u", ROBOTO_BEFORE_URL, ROBOTO_AFTER_URL]
+    expected_string_list = ROBOTO_EXTDIFF_EXPECTED.split("\n")
+
+    with pytest.raises(SystemExit):
+        run(args)
+
+    captured = capsys.readouterr()
+    res_string_list = captured.out.split("\n")
+    for x, line in enumerate(res_string_list):
+        # treat top two lines of the diff as comparison of first 3 chars only
+        if x in (0, 1):
+            assert line[0:2] == expected_string_list[x][0:2]
+        elif x in range(2, 10):
+            assert line == expected_string_list[x]
+        else:
+            # skip lines beyond first 10
+            pass
+
+
+def test_main_external_diff_color(capsys):
+    args = ["--external", "diff -u", "--color", ROBOTO_BEFORE_PATH, ROBOTO_AFTER_PATH]
+    expected_string_list = ROBOTO_EXTDIFF_COLOR_EXPECTED.split("\n")
+
+    with pytest.raises(SystemExit):
+        run(args)
+
+    captured = capsys.readouterr()
+    res_string_list = captured.out.split("\n")
+    for x, line in enumerate(res_string_list):
+        # treat top two lines of the diff as comparison of first 3 chars only
+        if x in (0, 1):
+            assert line[0:2] == expected_string_list[x][0:2]
+        elif x in range(2, 10):
+            assert line == expected_string_list[x]
+        else:
+            # skip lines beyond first 10
+            pass
+
+
+def test_main_external_diff_with_head_fails(capsys):
+    args = ["--external", "diff -u", "--head", "1", ROBOTO_BEFORE_PATH, ROBOTO_AFTER_PATH]
+
+    with pytest.raises(SystemExit) as exit_info:
+        run(args)
+
+    captured = capsys.readouterr()
+    assert "[ERROR] The head and tail options are not supported" in captured.err
+    assert exit_info.value.code == 1
+
+
+def test_main_external_diff_with_tail_fails(capsys):
+    args = ["--external", "diff -u", "--tail", "1", ROBOTO_BEFORE_PATH, ROBOTO_AFTER_PATH]
+
+    with pytest.raises(SystemExit) as exit_info:
+        run(args)
+
+    captured = capsys.readouterr()
+    assert "[ERROR] The head and tail options are not supported" in captured.err
+    assert exit_info.value.code == 1
+
+
+def test_main_external_diff_with_lines_fails(capsys):
+    args = ["--external", "diff -u", "--lines", "1", ROBOTO_BEFORE_PATH, ROBOTO_AFTER_PATH]
+
+    with pytest.raises(SystemExit) as exit_info:
+        run(args)
+
+    captured = capsys.readouterr()
+    assert "[ERROR] The lines option is not supported" in captured.err
+    assert exit_info.value.code == 1