From b3592e14ad55634e3189db4e9298f72a54102209 Mon Sep 17 00:00:00 2001
From: Alexander Whitestone <alexander@alexanderwhitestone.com>
Date: Wed, 15 Apr 2026 14:48:59 +0000
Subject: [PATCH] test: add tests for Performance Bottleneck Finder

Refs #171
---
 tests/test_perf_bottleneck_finder.py | 319 +++++++++++++++++++++++++++
 1 file changed, 319 insertions(+)
 create mode 100644 tests/test_perf_bottleneck_finder.py

diff --git a/tests/test_perf_bottleneck_finder.py b/tests/test_perf_bottleneck_finder.py
new file mode 100644
index 0000000..02f2ba3
--- /dev/null
+++ b/tests/test_perf_bottleneck_finder.py
@@ -0,0 +1,319 @@
+#!/usr/bin/env python3
+"""
+Tests for Performance Bottleneck Finder.
+"""
+
+import json
+import os
+import tempfile
+import textwrap
+from pathlib import Path
+
+import pytest
+
+# Add scripts to path
+import sys
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "scripts"))
+
+from perf_bottleneck_finder import (
+    Bottleneck,
+    PerfReport,
+    find_slow_tests_by_scan,
+    analyze_build_artifacts,
+    analyze_makefile_targets,
+    find_slow_imports,
+    generate_report,
+    format_markdown,
+    severity_sort_key,
+)
+
+
+class TestBottleneck:
+    """Test Bottleneck dataclass."""
+
+    def test_creation(self):
+        b = Bottleneck(
+            category="test",
+            name="test_foo",
+            duration_s=5.0,
+            severity="warning",
+            recommendation="Mock it"
+        )
+        assert b.category == "test"
+        assert b.name == "test_foo"
+        assert b.duration_s == 5.0
+        assert b.severity == "warning"
+        assert b.recommendation == "Mock it"
+        assert b.file_path is None
+        assert b.line_number is None
+
+    def test_with_location(self):
+        b = Bottleneck(
+            category="test",
+            name="test_bar",
+            duration_s=2.0,
+            severity="info",
+            recommendation="Consider",
+            file_path="tests/test_bar.py",
+            line_number=42
+        )
+        assert b.file_path == "tests/test_bar.py"
+        assert b.line_number == 42
+
+    def test_to_dict(self):
+        b = Bottleneck("test", "x", 1.0, "info", "y")
+        d = b.__dict__
+        assert "category" in d
+        assert "duration_s" in d
+
+
+class TestPerfReport:
+    """Test PerfReport dataclass."""
+
+    def test_creation(self):
+        report = PerfReport(
+            timestamp="2026-01-01T00:00:00Z",
+            repo_path="/tmp/repo"
+        )
+        assert report.timestamp == "2026-01-01T00:00:00Z"
+        assert report.bottlenecks == []
+        assert report.summary == {}
+
+    def test_to_dict(self):
+        report = PerfReport(
+            timestamp="2026-01-01T00:00:00Z",
+            repo_path="/tmp/repo",
+            bottlenecks=[Bottleneck("test", "x", 1.0, "info", "y")]
+        )
+        d = report.to_dict()
+        assert "bottlenecks" in d
+        assert len(d["bottlenecks"]) == 1
+
+
+class TestSeveritySort:
+    """Test severity sorting."""
+
+    def test_critical_first(self):
+        items = [
+            Bottleneck("test", "a", 1.0, "info", ""),
+            Bottleneck("test", "b", 0.5, "critical", ""),
+            Bottleneck("test", "c", 2.0, "warning", ""),
+        ]
+        items.sort(key=severity_sort_key)
+        assert items[0].severity == "critical"
+        assert items[1].severity == "warning"
+        assert items[2].severity == "info"
+
+    def test_duration_within_severity(self):
+        items = [
+            Bottleneck("test", "slow", 10.0, "warning", ""),
+            Bottleneck("test", "fast", 1.0, "warning", ""),
+        ]
+        items.sort(key=severity_sort_key)
+        assert items[0].name == "slow"  # Higher duration first within same severity
+
+
+class TestSlowTestScan:
+    """Test slow test pattern scanning."""
+
+    def test_finds_sleep(self, tmp_path):
+        test_file = tmp_path / "test_sleepy.py"
+        test_file.write_text(textwrap.dedent('''
+            import time
+
+            def test_slow():
+                time.sleep(5)
+                assert True
+        '''))
+
+        bottlenecks = find_slow_tests_by_scan(str(tmp_path))
+        assert len(bottlenecks) >= 1
+        assert any("sleep" in b.recommendation.lower() for b in bottlenecks)
+
+    def test_finds_http_calls(self, tmp_path):
+        test_file = tmp_path / "test_http.py"
+        test_file.write_text(textwrap.dedent('''
+            import requests
+
+            def test_api():
+                resp = requests.get("https://example.com")
+                assert resp.status_code == 200
+        '''))
+
+        bottlenecks = find_slow_tests_by_scan(str(tmp_path))
+        assert len(bottlenecks) >= 1
+        assert any("HTTP" in b.recommendation or "mock" in b.recommendation.lower() for b in bottlenecks)
+
+    def test_skips_non_test_files(self, tmp_path):
+        src_file = tmp_path / "main.py"
+        src_file.write_text("import time\ntime.sleep(10)\n")
+
+        bottlenecks = find_slow_tests_by_scan(str(tmp_path))
+        assert len(bottlenecks) == 0
+
+    def test_handles_missing_dir(self):
+        bottlenecks = find_slow_tests_by_scan("/nonexistent/path")
+        assert bottlenecks == []
+
+    def test_file_path_populated(self, tmp_path):
+        test_file = tmp_path / "test_example.py"
+        test_file.write_text("import time\n\ndef test_it():\n    time.sleep(2)\n")
+
+        bottlenecks = find_slow_tests_by_scan(str(tmp_path))
+        assert len(bottlenecks) >= 1
+        assert bottlenecks[0].file_path is not None
+        assert bottlenecks[0].line_number is not None
+
+
+class TestBuildArtifacts:
+    """Test build artifact analysis."""
+
+    def test_finds_large_node_modules(self, tmp_path):
+        nm = tmp_path / "node_modules"
+        nm.mkdir()
+        # Create a file > 10MB
+        big_file = nm / "big.txt"
+        big_file.write_bytes(b"x" * (11 * 1024 * 1024))
+
+        bottlenecks = analyze_build_artifacts(str(tmp_path))
+        assert len(bottlenecks) >= 1
+        assert any("node_modules" in b.name for b in bottlenecks)
+
+    def test_ignores_small_dirs(self, tmp_path):
+        nm = tmp_path / "node_modules"
+        nm.mkdir()
+        small_file = nm / "small.txt"
+        small_file.write_bytes(b"x" * 100)
+
+        bottlenecks = analyze_build_artifacts(str(tmp_path))
+        assert not any("node_modules" in b.name for b in bottlenecks)
+
+    def test_finds_pycache(self, tmp_path):
+        cache = tmp_path / "__pycache__"
+        cache.mkdir()
+        big_file = cache / "big.pyc"
+        big_file.write_bytes(b"x" * (11 * 1024 * 1024))
+
+        bottlenecks = analyze_build_artifacts(str(tmp_path))
+        assert any("__pycache__" in b.name for b in bottlenecks)
+
+
+class TestMakefileAnalysis:
+    """Test Makefile analysis."""
+
+    def test_finds_pip_install(self, tmp_path):
+        makefile = tmp_path / "Makefile"
+        makefile.write_text(textwrap.dedent('''
+            install:
+                pip install -r requirements.txt
+
+            test:
+                pytest
+        '''))
+
+        bottlenecks = analyze_makefile_targets(str(tmp_path))
+        assert len(bottlenecks) >= 1
+
+    def test_no_makefile(self, tmp_path):
+        bottlenecks = analyze_makefile_targets(str(tmp_path))
+        assert bottlenecks == []
+
+
+class TestImportAnalysis:
+    """Test heavy import detection."""
+
+    def test_finds_pandas(self, tmp_path):
+        src = tmp_path / "analysis.py"
+        src.write_text("import pandas as pd\n")
+
+        bottlenecks = find_slow_imports(str(tmp_path))
+        assert len(bottlenecks) >= 1
+        assert any("pandas" in b.name for b in bottlenecks)
+
+    def test_finds_torch(self, tmp_path):
+        src = tmp_path / "model.py"
+        src.write_text("import torch\n")
+
+        bottlenecks = find_slow_imports(str(tmp_path))
+        assert any("torch" in b.name for b in bottlenecks)
+
+    def test_skips_light_imports(self, tmp_path):
+        src = tmp_path / "utils.py"
+        src.write_text("import json\nimport os\nimport sys\n")
+
+        bottlenecks = find_slow_imports(str(tmp_path))
+        assert len(bottlenecks) == 0
+
+
+class TestGenerateReport:
+    """Test full report generation."""
+
+    def test_empty_repo(self, tmp_path):
+        report = generate_report(str(tmp_path))
+        assert report.summary["total_bottlenecks"] >= 0
+        assert "critical" in report.summary
+        assert "warning" in report.summary
+
+    def test_with_findings(self, tmp_path):
+        # Create a test file with issues
+        test_file = tmp_path / "test_slow.py"
+        test_file.write_text(textwrap.dedent('''
+            import time
+            import requests
+
+            def test_sleepy():
+                time.sleep(3)
+
+            def test_http():
+                requests.get("https://example.com")
+        '''))
+
+        report = generate_report(str(tmp_path))
+        assert report.summary["total_bottlenecks"] >= 2
+        assert len(report.bottlenecks) > 0
+
+    def test_summary_categories(self, tmp_path):
+        report = generate_report(str(tmp_path))
+        assert "by_category" in report.summary
+
+
+class TestMarkdownReport:
+    """Test markdown output."""
+
+    def test_format(self):
+        report = PerfReport(
+            timestamp="2026-01-01T00:00:00Z",
+            repo_path="/tmp/repo",
+            bottlenecks=[
+                Bottleneck("test", "slow_test", 5.0, "critical", "Fix it")
+            ],
+            summary={
+                "total_bottlenecks": 1,
+                "critical": 1,
+                "warning": 0,
+                "info": 0,
+                "estimated_total_slowdown_s": 5.0,
+                "by_category": {"test": 1},
+            }
+        )
+        md = format_markdown(report)
+        assert "# Performance Bottleneck Report" in md
+        assert "slow_test" in md
+        assert "🔴" in md
+        assert "Fix it" in md
+
+    def test_empty_report(self):
+        report = PerfReport(
+            timestamp="2026-01-01T00:00:00Z",
+            repo_path="/tmp/repo",
+            summary={
+                "total_bottlenecks": 0,
+                "critical": 0,
+                "warning": 0,
+                "info": 0,
+                "estimated_total_slowdown_s": 0,
+                "by_category": {},
+            }
+        )
+        md = format_markdown(report)
+        assert "Total bottlenecks:** 0" in md