Implement ASCII art only flag

README.md

@@ -45,6 +45,7 @@ You can run the `gh skyline` command with the following flags:
   - Examples: `gh skyline --year 2020`, `gh skyline --year 2014-2024`
 - `-w`, `--web`: Open the GitHub profile for the authenticated or specified user.
   - Example: `gh skyline --web`, `gh skyline --user mona --web`
+- `--art-only`: Show the ASCII art preview without generating an STL file. 
 
 ### Examples
 
@@ -78,6 +79,12 @@ Generate a skyline from the user's join year to the current year:
 gh skyline --full
 ```
 
+Generate only the ASCII preview for a skyline:
+
+```bash
+gh skyline --art-only
+```
+
 Enable debug logging:
 
 ```bash

ascii/generator.go

@@ -16,7 +16,7 @@ var ErrInvalidGrid = errors.New("invalid contribution grid")
 // GenerateASCII creates a 2D ASCII art representation of the contribution data.
 // It returns the generated ASCII art as a string and an error if the operation fails.
 // When includeHeader is true, the output includes the header template.
-func GenerateASCII(contributionGrid [][]types.ContributionDay, username string, year int, includeHeader bool) (string, error) {
+func GenerateASCII(contributionGrid [][]types.ContributionDay, username string, year int, includeHeader bool, includeUserInfo bool) (string, error) {
 	if len(contributionGrid) == 0 {
 		return "", ErrInvalidGrid
 	}
@@ -74,10 +74,12 @@ func GenerateASCII(contributionGrid [][]types.ContributionDay, username string,
 		buffer.WriteRune('\n')
 	}
 
-	// Add centered user info below
-	buffer.WriteString("\n")
-	buffer.WriteString(centerText(username))
-	buffer.WriteString(centerText(fmt.Sprintf("%d", year)))
+	if includeUserInfo {
+		// Add centered user info below
+		buffer.WriteString("\n")
+		buffer.WriteString(centerText(username))
+		buffer.WriteString(centerText(fmt.Sprintf("%d", year)))
+	}
 
 	return buffer.String(), nil
 }

ascii/generator_test.go

@@ -32,16 +32,24 @@ func TestGenerateASCII(t *testing.T) {
 			includeHeader: false,
 			wantErr:       false,
 		},
+		{
+			name:          "no header",
+			grid:          makeTestGrid(3, 7),
+			user:          "testuser",
+			year:          2023,
+			includeHeader: false,
+			wantErr:       false,
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			result, err := GenerateASCII(tt.grid, tt.user, tt.year, tt.includeHeader)
+			result, err := GenerateASCII(tt.grid, tt.user, tt.year, tt.includeHeader, tt.includeHeader)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("GenerateASCII() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
-			if !tt.wantErr {
+			if !tt.wantErr && tt.includeHeader {
 				// Existing validation code...
 				if !strings.Contains(result, "testuser") {
 					t.Error("Generated ASCII should contain username")
@@ -52,6 +60,20 @@ func TestGenerateASCII(t *testing.T) {
 				if !strings.Contains(result, string(EmptyBlock)) {
 					t.Error("Generated ASCII should contain empty blocks")
 				}
+				if !strings.Contains(result, HeaderTemplate) {
+					t.Error("Generated ASCII should contain header")
+				}
+			}
+			if !tt.wantErr && !tt.includeHeader {
+				if strings.Contains(result, "testuser") {
+					t.Error("Generated ASCII should exclude username when requested")
+				}
+				if strings.Contains(result, "2023") {
+					t.Error("Generated ASCII should exclude year when requested")
+				}
+				if strings.Contains(result, HeaderTemplate) {
+					t.Error("Generated ASCII should exclude header when requested")
+				}
 			}
 		})
 	}

main.go

@@ -45,6 +45,7 @@ var (
 	full      bool
 	debug     bool
 	web       bool
+	artOnly   bool
 	output    string // new output path flag
 
 	rootCmd = &cobra.Command{
@@ -106,6 +107,7 @@ func init() {
 	rootCmd.Flags().BoolVarP(&full, "full", "f", false, "Generate contribution graph from join year to current year")
 	rootCmd.Flags().BoolVarP(&debug, "debug", "d", false, "Enable debug logging")
 	rootCmd.Flags().BoolVarP(&web, "web", "w", false, "Open GitHub profile (authenticated or specified user).")
+	rootCmd.Flags().BoolVar(&artOnly, "art-only", false, "Generate only ASCII preview")
 	rootCmd.Flags().StringVarP(&output, "output", "o", "", "Output file path (optional)")
 }
 
@@ -176,7 +178,7 @@ func generateSkyline(startYear, endYear int, targetUser string, full bool) error
 		allContributions = append(allContributions, contributions)
 
 		// Generate ASCII art for each year
-		asciiArt, err := ascii.GenerateASCII(contributions, targetUser, year, year == startYear)
+		asciiArt, err := ascii.GenerateASCII(contributions, targetUser, year, (year == startYear) && !artOnly, !artOnly)
 		if err != nil {
 			if warnErr := log.Warning("Failed to generate ASCII preview: %v", err); warnErr != nil {
 				return warnErr
@@ -202,14 +204,18 @@ func generateSkyline(startYear, endYear int, targetUser string, full bool) error
 		}
 	}
 
-	// Generate filename
-	outputPath := generateOutputFilename(targetUser, startYear, endYear)
+	if !artOnly {
+		// Generate filename
+		outputPath := generateOutputFilename(targetUser, startYear, endYear)
 
-	// Generate the STL file
-	if len(allContributions) == 1 {
-		return stl.GenerateSTL(allContributions[0], outputPath, targetUser, startYear)
+		// Generate the STL file
+		if len(allContributions) == 1 {
+			return stl.GenerateSTL(allContributions[0], outputPath, targetUser, startYear)
+		}
+		return stl.GenerateSTLRange(allContributions, outputPath, targetUser, startYear, endYear)
 	}
-	return stl.GenerateSTLRange(allContributions, outputPath, targetUser, startYear, endYear)
+
+	return nil
 }
 
 // Variable for client initialization - allows for testing