test: add comprehensive testing of codegen (#14)

codegen/download_test.go

@@ -0,0 +1,141 @@
+package main
+
+import (
+	"archive/zip"
+	"net/url"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// Helper function to create a temporary zip file with given entries. 'entries' maps file names to their content.
+func createTempZipFile(t *testing.T, entries map[string]string) string {
+	t.Helper()
+	tempDir := t.TempDir()
+	tempFileName := filepath.Join(tempDir, "test.zip")
+	tempFile, err := os.Create(tempFileName)
+	require.NoError(t, err, "Failed to create temp zip file")
+	// We need to truncate and write zip contents
+	w := zip.NewWriter(tempFile)
+	for name, content := range entries {
+		f, err := w.Create(name)
+		require.NoError(t, err, "Failed to add entry %s", name)
+		_, err = f.Write([]byte(content))
+		require.NoError(t, err, "Failed to write content for %s", name)
+	}
+	err = w.Close()
+	require.NoError(t, err, "Failed to close zip writer")
+	err = tempFile.Close()
+	require.NoError(t, err, "Failed to close temp file")
+	return tempFile.Name()
+}
+
+// Test when the output directory already exists. In this case, DownloadAndExtract should not call downloadJarFn or extractJSONFn.
+func TestDownloadAndExtract_WithExistingDirectory(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+
+	tempDir := t.TempDir()
+	testURL, _ := url.Parse("http://example.com/test.deb")
+
+	err := DownloadAndExtract(*testURL, tempDir)
+
+	r.NoError(err, "Expected no error when directory exists")
+}
+
+// // Test when output path is not a directory.
+func TestDownloadAndExtract_PathNotDirectory(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+
+	tempDir := t.TempDir()
+	tempFilePath := filepath.Join(tempDir, "dummy")
+	_, err := os.Create(tempFilePath)
+	r.NoError(err, "Failed to create temp file")
+	testURL, _ := url.Parse("http://example.com/test.deb")
+
+	err = DownloadAndExtract(*testURL, tempFilePath)
+
+	r.Error(err, "Expected error because tempFilePath is not a directory")
+	r.ErrorContains(err, tempFilePath+" isn't a directory")
+}
+
+// // Test extractJSON when the jar file cannot be opened.
+func TestExtractJSON_OpenJarError(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+
+	err := extractJSON("nonexisting.jar", t.TempDir())
+
+	r.Error(err)
+	r.ErrorContains(err, "unable to open jar")
+}
+
+// Test extractJSON with a valid zip file that contains a JSON file under api/fields/ and no Setting.json (so splitting is skipped).
+func TestExtractJSON_NoSettings(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+	tempDir := t.TempDir()
+	jarFile := createTempZipFile(t, map[string]string{"api/fields/dummy.json": "{\"key\": \"value\"}"})
+
+	err := extractJSON(jarFile, tempDir)
+	r.NoError(err)
+
+	// Check that dummy.json has been extracted
+	expectedPath := filepath.Join(tempDir, "dummy.json")
+	data, err := os.ReadFile(expectedPath)
+	r.NoError(err, "Expected file %s to exist", expectedPath)
+	r.JSONEq("{\"key\": \"value\"}", string(data), "Extracted file content mismatch")
+}
+
+// Test extractJSON with Setting.json present, so that it splits settings into individual files.
+func TestExtractJSON_WithSettings(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+	tempDir := t.TempDir()
+	entries := map[string]string{"api/fields/Setting.json": "{\"foo\": {\"bar\": 1}}"}
+	jarFile := createTempZipFile(t, entries)
+
+	err := extractJSON(jarFile, tempDir)
+	r.NoError(err)
+
+	// Check that the split settings file exists
+	settingFile := filepath.Join(tempDir, "SettingFoo.json")
+	data, err := os.ReadFile(settingFile)
+	r.NoError(err)
+	r.Contains(string(data), "bar")
+}
+
+// Test sanitizeExtractedPath with valid input.
+func TestSanitizeExtractedPath_Valid(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	r := require.New(t)
+
+	tempDir := t.TempDir()
+	filePath := "api/fields/dummy.json"
+
+	result, err := sanitizeExtractedPath(filePath, tempDir)
+	r.NoError(err, "Expected nil error from sanitizeExtractedPath")
+
+	expExpected := filepath.Join(tempDir, "dummy.json")
+	absExpected, err := filepath.Abs(expExpected)
+	r.NoError(err, "Failed to get abs path")
+	a.Equal(absExpected, result, "Sanitized path mismatch")
+}
+
+// Test extractJSON with invalid Setting.json content, expecting an unmarshal error.
+func TestExtractJSON_InvalidSettings(t *testing.T) {
+	t.Parallel()
+	r := require.New(t)
+	tempDir := t.TempDir()
+	jarFile := createTempZipFile(t, map[string]string{"api/fields/Setting.json": "invalid json"})
+
+	err := extractJSON(jarFile, tempDir)
+
+	r.Error(err)
+	r.ErrorContains(err, "unable to unmarshal settings")
+}