feat: Add configurable table styles for coverage output

.go-covercheck.history.json

@@ -1,5 +1,50 @@
 {
   "entries": [
+    {
+      "commit": "a33d6daaa0cea52472df889a1e6a04490fa41151",
+      "branch": "copilot/fix-42",
+      "timestamp": "2025-08-02T06:01:01.917674791Z",
+      "results": {
+        "byFile": [
+          {
+            "statementCoverage": "1/2",
+            "blockCoverage": "1/2",
+            "statementPercentage": 50,
+            "blockPercentage": 50,
+            "statementThreshold": 65,
+            "blockThreshold": 50,
+            "failed": true,
+            "file": "github.com/mach6/go-covercheck/pkg/math/math.go"
+          }
+        ],
+        "byPackage": [
+          {
+            "statementCoverage": "1/2",
+            "blockCoverage": "1/2",
+            "statementPercentage": 50,
+            "blockPercentage": 50,
+            "statementThreshold": 65,
+            "blockThreshold": 50,
+            "failed": true,
+            "package": "github.com/mach6/go-covercheck/pkg/math"
+          }
+        ],
+        "byTotal": {
+          "statements": {
+            "coverage": "1/2",
+            "threshold": 80,
+            "percentage": 50,
+            "failed": true
+          },
+          "blocks": {
+            "coverage": "1/2",
+            "threshold": 75,
+            "percentage": 50,
+            "failed": true
+          }
+        }
+      }
+    },
     {
       "commit": "ef613d597be47cdeaa401aebee56ef0605eb4f8b",
       "branch": "detached",
@@ -542,4 +587,4 @@
       }
     }
   ]
-}
+}

README.md

@@ -14,6 +14,7 @@ A fast, flexible CLI tool for enforcing test coverage thresholds in Go projects.
 - Enforce minimum coverage thresholds for files, packages, and the entire project.
 - Supports statement and block coverage separately.
 - Native `table`|`json`|`yaml`|`md`|`html`|`csv`|`tsv` output.
+- Configurable table styles (`default`|`light`|`bold`|`rounded`|`double`).
 - Configurable via a `.go-covercheck.yml` or CLI flags.
 - Sorting and colored table output.
 - Colored `json` and `yaml` output.
@@ -27,7 +28,6 @@ The following items are noteworthy and not (currently) supported.
 
 - Does not support configurable profile block count (how many times a section of code was hit) thresholds. The assumption
   is any value `>=1` is enough.
-- Table style is not configurable.
 - Color codes (see [Color Legend](#🎨-color-legend)) are not configurable.
 - Severity weights (see [Color Legend](#🎨-color-legend)) are not configurable.
 
@@ -111,6 +111,9 @@ Here is a sample `.go-covercheck.yml` configuration file:
 statementThreshold: 65.0
 blockThreshold: 60.0
 
+# Optional, table style for table output format (default: light)
+tableStyle: bold
+
 # Optional, by total thresholds overriding the global values above
 total:
   statements: 75.0
@@ -202,6 +205,26 @@ Flags:
   -v, --version                           version for go-covercheck
 ```
 
+### 🎨 Table Styles
+
+You can customize the appearance of table output using the `--table-style` flag or by configuring `tableStyle` in your `.go-covercheck.yml` file.
+
+Available table styles:
+- `default` - ASCII characters (compatible with all terminals)
+- `light` - Unicode light box drawing characters (default)
+- `bold` - Unicode bold box drawing characters  
+- `rounded` - Unicode rounded corner characters
+- `double` - Unicode double line characters
+
+**Example:**
+```shell
+# Use bold table style via CLI
+go-covercheck --table-style=bold
+
+# Use rounded table style via config file
+echo "tableStyle: rounded" >> .go-covercheck.yml
+```
+
 ## 🕰️ History
 
 History is a feature that allows you to save and compare coverage results against previous runs.

cmd/go-covercheck/root.go

@@ -37,6 +37,9 @@ const (
 	FormatFlag      = "format"
 	FormatFlagShort = "f"
 
+	TableStyleFlag      = "table-style"
+	TableStyleFlagUsage = "table style [default|light|bold|rounded|double]"
+
 	StatementThresholdFlag      = "statement-threshold"
 	StatementThresholdFlagShort = "s"
 	StatementThresholdFlagUsage = "global statement threshold to enforce [0=disabled]"
@@ -453,6 +456,10 @@ func applyConfigOverrides(cfg *config.Config, cmd *cobra.Command, noConfigFile b
 		noConfigFile {
 		cfg.Format = v
 	}
+	if v, _ := cmd.Flags().GetString(TableStyleFlag); cmd.Flags().Changed(TableStyleFlag) ||
+		noConfigFile {
+		cfg.TableStyle = v
+	}
 	if v, _ := cmd.Flags().GetBool(NoTableFlag); cmd.Flags().Changed(NoTableFlag) ||
 		noConfigFile {
 		cfg.NoTable = v
@@ -538,6 +545,12 @@ func initFlags(cmd *cobra.Command) {
 		FormatFlagUsage,
 	)
 
+	cmd.Flags().String(
+		TableStyleFlag,
+		config.TableStyleDefValue,
+		TableStyleFlagUsage,
+	)
+
 	cmd.Flags().Float64P(
 		StatementThresholdFlag,
 		StatementThresholdFlagShort,

pkg/config/config.go

@@ -40,6 +40,13 @@ const (
 	FormatMD      = "md"
 	FormatDefault = FormatTable
 
+	TableStyleDefault = "default"
+	TableStyleLight   = "light"
+	TableStyleBold    = "bold"
+	TableStyleRounded = "rounded"
+	TableStyleDouble  = "double"
+	TableStyleDefValue = TableStyleLight
+
 	thresholdOff = 0
 	thresholdMax = 100
 
@@ -78,6 +85,7 @@ type Config struct {
 	NoSummary          bool                 `yaml:"noSummary,omitempty"`
 	NoColor            bool                 `yaml:"noColor,omitempty"`
 	Format             string               `yaml:"format,omitempty"`
+	TableStyle         string               `yaml:"tableStyle,omitempty"`
 	TerminalWidth      int                  `yaml:"terminalWidth,omitempty"`
 	ModuleName         string               `yaml:"moduleName,omitempty"`
 }
@@ -110,6 +118,7 @@ func (c *Config) ApplyDefaults() {
 	c.SortOrder = SortOrderDefault
 	c.Skip = []string{}
 	c.Format = FormatDefault
+	c.TableStyle = TableStyleDefValue
 
 	c.initPerFileWhenNil()
 	c.initPerPackageWhenNil()
@@ -148,6 +157,14 @@ func (c *Config) Validate() error { //nolint:cyclop
 			FormatJSON, FormatYAML, FormatTable, FormatCSV, FormatHTML, FormatTSV, FormatMD)
 	}
 
+	switch c.TableStyle {
+	case TableStyleDefault, TableStyleLight, TableStyleBold, TableStyleRounded, TableStyleDouble:
+		break
+	default:
+		return fmt.Errorf("table-style must be one of %s|%s|%s|%s|%s",
+			TableStyleDefault, TableStyleLight, TableStyleBold, TableStyleRounded, TableStyleDouble)
+	}
+
 	if c.NoSummary && c.NoTable && c.Format != FormatJSON && c.Format != FormatYAML {
 		return fmt.Errorf("cannot specify both no-summary and no-table with format %s", c.Format)
 	}

pkg/config/config_test.go

@@ -44,3 +44,64 @@ func TestLoad_InvalidYAML(t *testing.T) {
 	require.Error(t, err)
 	require.Nil(t, cfg)
 }
+
+func TestLoad_ValidYAML_WithTableStyle(t *testing.T) {
+	yaml := `
+statementThreshold: 75.0
+tableStyle: bold
+`
+	tmpFile := path.Join(t.TempDir(), "test_config_table_style.yaml")
+	err := os.WriteFile(tmpFile, []byte(yaml), 0600)
+	require.NoError(t, err)
+	defer os.Remove(tmpFile) //nolint:errcheck
+
+	cfg, err := config.Load(tmpFile)
+	require.NoError(t, err)
+	require.Equal(t, "bold", cfg.TableStyle)
+}
+
+func TestApplyDefaults_TableStyle(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.ApplyDefaults()
+	require.Equal(t, config.TableStyleDefValue, cfg.TableStyle)
+	require.Equal(t, "light", cfg.TableStyle) // Should be light by default
+}
+
+func TestValidate_InvalidTableStyle(t *testing.T) {
+	cfg := &config.Config{
+		StatementThreshold: 70,
+		BlockThreshold:     50,
+		SortBy:             "file",
+		SortOrder:          "asc",
+		Format:             "table",
+		TableStyle:         "invalid",
+	}
+	err := cfg.Validate()
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "table-style must be one of")
+}
+
+func TestValidate_ValidTableStyles(t *testing.T) {
+	validStyles := []string{
+		config.TableStyleDefault,
+		config.TableStyleLight,
+		config.TableStyleBold,
+		config.TableStyleRounded,
+		config.TableStyleDouble,
+	}
+
+	for _, style := range validStyles {
+		t.Run(style, func(t *testing.T) {
+			cfg := &config.Config{
+				StatementThreshold: 70,
+				BlockThreshold:     50,
+				SortBy:             "file",
+				SortOrder:          "asc",
+				Format:             "table",
+				TableStyle:         style,
+			}
+			err := cfg.Validate()
+			require.NoError(t, err)
+		})
+	}
+}

pkg/output/history.go

@@ -13,6 +13,55 @@ import (
 	"github.com/mach6/go-covercheck/pkg/history"
 )
 
+// getHistoryTableStyle returns the appropriate table.Style for history tables.
+func getHistoryTableStyle(cfg *config.Config) table.Style {
+	var boxStyle table.BoxStyle
+
+	switch cfg.TableStyle {
+	case config.TableStyleDefault:
+		boxStyle = table.StyleBoxDefault
+	case config.TableStyleBold:
+		boxStyle = table.StyleBoxBold
+	case config.TableStyleRounded:
+		boxStyle = table.StyleBoxRounded
+	case config.TableStyleDouble:
+		boxStyle = table.StyleBoxDouble
+	default: // config.TableStyleLight or any other value
+		boxStyle = table.StyleBoxLight
+	}
+
+	return table.Style{
+		Name:  "Custom",
+		Box:   boxStyle,
+		Color: table.ColorOptionsDefault,
+		Format: table.FormatOptions{
+			Footer:       text.FormatDefault,
+			FooterAlign:  text.AlignRight,
+			FooterVAlign: text.VAlignDefault,
+			Header:       text.FormatUpper,
+			HeaderAlign:  text.AlignCenter,
+			HeaderVAlign: text.VAlignDefault,
+			Row:          text.FormatDefault,
+			RowAlign:     text.AlignRight,
+			RowVAlign:    text.VAlignDefault,
+		},
+		HTML: table.DefaultHTMLOptions,
+		Options: table.Options{
+			DoNotColorBordersAndSeparators: false,
+			DrawBorder:                     true,
+			SeparateColumns:                true,
+			SeparateFooter:                 true,
+			SeparateHeader:                 true,
+			SeparateRows:                   true,
+		},
+		Size: table.SizeOptions{
+			WidthMax: cfg.TerminalWidth,
+			WidthMin: 0,
+		},
+		Title: table.TitleOptionsDefault,
+	}
+}
+
 // CompareHistory shows the comparison output for a ref: and the results.
 func CompareHistory(ref string, refEntry *history.Entry, results compute.Results) {
 	fmt.Printf("\n≡ Comparing against ref: %s [commit %s]\n",
@@ -122,38 +171,7 @@ func ShowHistory(h *history.History, limit int, cfg *config.Config) {
 
 	t := table.NewWriter()
 	t.SetOutputMirror(os.Stdout)
-	t.SetStyle(
-		table.Style{
-			Name:  "Custom",
-			Box:   table.StyleBoxLight,
-			Color: table.ColorOptionsDefault,
-			Format: table.FormatOptions{
-				Footer:       text.FormatDefault,
-				FooterAlign:  text.AlignRight,
-				FooterVAlign: text.VAlignDefault,
-				Header:       text.FormatUpper,
-				HeaderAlign:  text.AlignCenter,
-				HeaderVAlign: text.VAlignDefault,
-				Row:          text.FormatDefault,
-				RowAlign:     text.AlignRight,
-				RowVAlign:    text.VAlignDefault,
-			},
-			HTML: table.DefaultHTMLOptions,
-			Options: table.Options{
-				DoNotColorBordersAndSeparators: false,
-				DrawBorder:                     true,
-				SeparateColumns:                true,
-				SeparateFooter:                 true,
-				SeparateHeader:                 true,
-				SeparateRows:                   true,
-			},
-			Size: table.SizeOptions{
-				WidthMax: cfg.TerminalWidth,
-				WidthMin: 0,
-			},
-			Title: table.TitleOptionsDefault,
-		},
-	)
+	t.SetStyle(getHistoryTableStyle(cfg))
 
 	t.AppendHeader(table.Row{"Timestamp", "Commit", "Branch", "Tags", "Label", "Coverage"})