refactor: Align with Go conventions and improve maintainability

Renames the `OriginalUrl` field to `OriginalURL` across media models to adhere to Go's common initialisms convention. The `json` tag is unchanged to maintain API compatibility.

Introduces constants for exporter formats (e.g., `FormatMarkdown`, `FormatDocx`) to eliminate the use of magic strings, enhancing type safety and making the code easier to maintain.

Additionally, this commit includes several minor code quality improvements:
- Wraps file-writing errors in exporters to provide more context.
- Removes redundant package-level comments from test files.
- Applies various minor linting fixes throughout the codebase.

Author: kjanat

.github/workflows/ci.yml

@@ -467,7 +467,7 @@ jobs:
           # Process a local file (mount current directory)
           docker run --rm -v $(pwd):/workspace ghcr.io/${{ github.repository }}:latest /workspace/input.json markdown /workspace/output.md
           ```
-          
+
           EOF
 
   # Security and quality analysis workflows

internal/config/config_test.go

@@ -1,4 +1,3 @@
-// Package config_test provides tests for the config package.
 package config
 
 import (

internal/exporters/bench_test.go

@@ -1,4 +1,3 @@
-// Package exporters_test provides benchmarks for all exporters.
 package exporters
 
 import (

internal/exporters/docx.go

@@ -69,7 +69,7 @@ func (e *DocxExporter) Export(course *models.Course, outputPath string) error {
 
 	// Ensure output directory exists and add .docx extension
 	if !strings.HasSuffix(strings.ToLower(outputPath), ".docx") {
-		outputPath = outputPath + ".docx"
+		outputPath += ".docx"
 	}
 
 	// Create the file
@@ -198,5 +198,5 @@ func (e *DocxExporter) exportSubItem(doc *docx.Docx, subItem *models.SubItem) {
 // Returns:
 //   - A string representing the supported format ("docx")
 func (e *DocxExporter) SupportedFormat() string {
-	return "docx"
+	return FormatDocx
 }

internal/exporters/docx_test.go

@@ -1,4 +1,3 @@
-// Package exporters_test provides tests for the docx exporter.
 package exporters
 
 import (
@@ -331,7 +330,7 @@ func TestDocxExporter_ComplexCourse(t *testing.T) {
 									Caption: "<p>Watch this introductory video</p>",
 									Media: &models.Media{
 										Video: &models.VideoMedia{
-											OriginalUrl: "https://example.com/intro.mp4",
+											OriginalURL: "https://example.com/intro.mp4",
 											Duration:    300,
 										},
 									},
@@ -359,7 +358,7 @@ func TestDocxExporter_ComplexCourse(t *testing.T) {
 									Caption: "<p>Course overview diagram</p>",
 									Media: &models.Media{
 										Image: &models.ImageMedia{
-											OriginalUrl: "https://example.com/overview.png",
+											OriginalURL: "https://example.com/overview.png",
 										},
 									},
 								},

internal/exporters/factory.go

@@ -1,5 +1,3 @@
-// Package exporters provides implementations of the Exporter interface
-// for converting Articulate Rise courses into various file formats.
 package exporters
 
 import (
@@ -10,6 +8,13 @@ import (
 	"github.com/kjanat/articulate-parser/internal/services"
 )
 
+// Format constants for supported export formats.
+const (
+	FormatMarkdown = "markdown"
+	FormatDocx     = "docx"
+	FormatHTML     = "html"
+)
+
 // Factory implements the ExporterFactory interface.
 // It creates appropriate exporter instances based on the requested format.
 type Factory struct {
@@ -36,11 +41,11 @@ func NewFactory(htmlCleaner *services.HTMLCleaner) interfaces.ExporterFactory {
 // Format strings are case-insensitive (e.g., "markdown", "DOCX").
 func (f *Factory) CreateExporter(format string) (interfaces.Exporter, error) {
 	switch strings.ToLower(format) {
-	case "markdown", "md":
+	case FormatMarkdown, "md":
 		return NewMarkdownExporter(f.htmlCleaner), nil
-	case "docx", "word":
+	case FormatDocx, "word":
 		return NewDocxExporter(f.htmlCleaner), nil
-	case "html", "htm":
+	case FormatHTML, "htm":
 		return NewHTMLExporter(f.htmlCleaner), nil
 	default:
 		return nil, fmt.Errorf("unsupported export format: %s", format)
@@ -50,5 +55,5 @@ func (f *Factory) CreateExporter(format string) (interfaces.Exporter, error) {
 // SupportedFormats returns a list of all supported export formats,
 // including both primary format names and their aliases.
 func (f *Factory) SupportedFormats() []string {
-	return []string{"markdown", "md", "docx", "word", "html", "htm"}
+	return []string{FormatMarkdown, "md", FormatDocx, "word", FormatHTML, "htm"}
 }

internal/exporters/factory_test.go

@@ -1,4 +1,3 @@
-// Package exporters_test provides tests for the exporter factory.
 package exporters
 
 import (

internal/exporters/html.go

@@ -1,5 +1,3 @@
-// Package exporters provides implementations of the Exporter interface
-// for converting Articulate Rise courses into various file formats.
 package exporters
 
 import (
@@ -112,7 +110,10 @@ func (e *HTMLExporter) Export(course *models.Course, outputPath string) error {
 	buf.WriteString("</html>\n")
 
 	// #nosec G306 - 0644 is appropriate for export files that should be readable by others
-	return os.WriteFile(outputPath, buf.Bytes(), 0o644)
+	if err := os.WriteFile(outputPath, buf.Bytes(), 0o644); err != nil {
+		return fmt.Errorf("failed to write HTML file: %w", err)
+	}
+	return nil
 }
 
 // SupportedFormat returns the format name this exporter supports
@@ -121,7 +122,7 @@ func (e *HTMLExporter) Export(course *models.Course, outputPath string) error {
 // Returns:
 //   - A string representing the supported format ("html")
 func (e *HTMLExporter) SupportedFormat() string {
-	return "html"
+	return FormatHTML
 }
 
 // getDefaultCSS returns basic CSS styling for the HTML document.
@@ -390,7 +391,7 @@ func (e *HTMLExporter) processMultimediaItem(buf *bytes.Buffer, item models.Item
 		if subItem.Media != nil {
 			if subItem.Media.Video != nil {
 				buf.WriteString("            <div class=\"media-info\">\n")
-				fmt.Fprintf(buf, "                <p><strong>Video:</strong> %s</p>\n", html.EscapeString(subItem.Media.Video.OriginalUrl))
+				fmt.Fprintf(buf, "                <p><strong>Video:</strong> %s</p>\n", html.EscapeString(subItem.Media.Video.OriginalURL))
 				if subItem.Media.Video.Duration > 0 {
 					fmt.Fprintf(buf, "                <p><strong>Duration:</strong> %d seconds</p>\n", subItem.Media.Video.Duration)
 				}
@@ -411,7 +412,7 @@ func (e *HTMLExporter) processImageItem(buf *bytes.Buffer, item models.Item) {
 	for _, subItem := range item.Items {
 		if subItem.Media != nil && subItem.Media.Image != nil {
 			buf.WriteString("            <div class=\"media-info\">\n")
-			fmt.Fprintf(buf, "                <p><strong>Image:</strong> %s</p>\n", html.EscapeString(subItem.Media.Image.OriginalUrl))
+			fmt.Fprintf(buf, "                <p><strong>Image:</strong> %s</p>\n", html.EscapeString(subItem.Media.Image.OriginalURL))
 			buf.WriteString("            </div>\n")
 		}
 		if subItem.Caption != "" {

internal/exporters/html_test.go

@@ -1,4 +1,3 @@
-// Package exporters_test provides tests for the html exporter.
 package exporters
 
 import (
@@ -270,7 +269,7 @@ func TestHTMLExporter_ProcessMultimediaItem(t *testing.T) {
 				Title: "<p>Video Title</p>",
 				Media: &models.Media{
 					Video: &models.VideoMedia{
-						OriginalUrl: "https://example.com/video.mp4",
+						OriginalURL: "https://example.com/video.mp4",
 						Duration:    120,
 					},
 				},
@@ -315,7 +314,7 @@ func TestHTMLExporter_ProcessImageItem(t *testing.T) {
 			{
 				Media: &models.Media{
 					Image: &models.ImageMedia{
-						OriginalUrl: "https://example.com/image.png",
+						OriginalURL: "https://example.com/image.png",
 					},
 				},
 				Caption: "<p>Image caption</p>",

internal/exporters/markdown.go

@@ -1,5 +1,3 @@
-// Package exporters provides implementations of the Exporter interface
-// for converting Articulate Rise courses into various file formats.
 package exporters
 
 import (
@@ -82,12 +80,15 @@ func (e *MarkdownExporter) Export(course *models.Course, outputPath string) erro
 	}
 
 	// #nosec G306 - 0644 is appropriate for export files that should be readable by others
-	return os.WriteFile(outputPath, buf.Bytes(), 0o644)
+	if err := os.WriteFile(outputPath, buf.Bytes(), 0o644); err != nil {
+		return fmt.Errorf("failed to write markdown file: %w", err)
+	}
+	return nil
 }
 
 // SupportedFormat returns "markdown".
 func (e *MarkdownExporter) SupportedFormat() string {
-	return "markdown"
+	return FormatMarkdown
 }
 
 // processItemToMarkdown converts a course item into Markdown format.
@@ -170,7 +171,7 @@ func (e *MarkdownExporter) processMediaSubItem(buf *bytes.Buffer, subItem models
 // processVideoMedia processes video media content.
 func (e *MarkdownExporter) processVideoMedia(buf *bytes.Buffer, media *models.Media) {
 	if media.Video != nil {
-		fmt.Fprintf(buf, "**Video**: %s\n", media.Video.OriginalUrl)
+		fmt.Fprintf(buf, "**Video**: %s\n", media.Video.OriginalURL)
 		if media.Video.Duration > 0 {
 			fmt.Fprintf(buf, "**Duration**: %d seconds\n", media.Video.Duration)
 		}
@@ -180,7 +181,7 @@ func (e *MarkdownExporter) processVideoMedia(buf *bytes.Buffer, media *models.Me
 // processImageMedia processes image media content.
 func (e *MarkdownExporter) processImageMedia(buf *bytes.Buffer, media *models.Media) {
 	if media.Image != nil {
-		fmt.Fprintf(buf, "**Image**: %s\n", media.Image.OriginalUrl)
+		fmt.Fprintf(buf, "**Image**: %s\n", media.Image.OriginalURL)
 	}
 }
 
@@ -189,7 +190,7 @@ func (e *MarkdownExporter) processImageItem(buf *bytes.Buffer, item models.Item,
 	fmt.Fprintf(buf, "%s Image\n\n", headingPrefix)
 	for _, subItem := range item.Items {
 		if subItem.Media != nil && subItem.Media.Image != nil {
-			fmt.Fprintf(buf, "**Image**: %s\n", subItem.Media.Image.OriginalUrl)
+			fmt.Fprintf(buf, "**Image**: %s\n", subItem.Media.Image.OriginalURL)
 		}
 		if subItem.Caption != "" {
 			caption := e.htmlCleaner.CleanHTML(subItem.Caption)