Convert color tests to pytest

.changes/unreleased/Under the Hood-20221108-133104.yaml

@@ -0,0 +1,7 @@
+kind: Under the Hood
+body: Convert use color tests to pytest
+time: 2022-11-08T13:31:04.788547-06:00
+custom:
+  Author: stu-k
+  Issue: "5771"
+  PR: "6230"

tests/functional/colors/test_colors.py

@@ -0,0 +1,43 @@
+import pytest
+import re
+from dbt.tests.util import run_dbt_and_capture
+
+
+models__do_nothing_then_fail_sql = """
+select 1,
+
+"""
+
+
+@pytest.fixture(scope="class")
+def models():
+    return {"do_nothing_then_fail.sql": models__do_nothing_then_fail_sql}
+
+
+@pytest.fixture(scope="class")
+def project_config_update():
+    return {'config-version': 2}
+
+
+class TestColors:
+    def test_use_colors(self, project):
+        self.assert_colors_used(
+            "--use-colors",
+            expect_colors=True,
+        )
+
+    def test_no_use_colors(self, project):
+        self.assert_colors_used(
+            "--no-use-colors",
+            expect_colors=False,
+        )
+
+    def assert_colors_used(self, flag, expect_colors):
+        _, stdout = run_dbt_and_capture(args=[flag, "run"], expect_pass=False)
+        # pattern to match formatted log output
+        pattern = re.compile(r"\[31m.*|\[33m.*")
+        stdout_contains_formatting_characters = bool(pattern.search(stdout))
+        if expect_colors:
+            assert stdout_contains_formatting_characters
+        else:
+            assert not stdout_contains_formatting_characters