Supertaining (#8)

Author: leefernandes

README.md

@@ -19,6 +19,9 @@ import (
 var ErrUserNotFound errific.Err = "user not found"
 
 func main() {
+	// Configure pretty JSON output for readability
+	errific.Configure(errific.OutputJSONPretty)
+
 	// Return an error with context
 	err := GetUser("user-123")
 	fmt.Println(err)
@@ -36,15 +39,23 @@ func GetUser(userID string) error {
 ```
 
 **Output:**
-```
-user not found [main.go:20.GetUser]
+```json
+{
+  "error": "user not found",
+  "code": "USER_404",
+  "caller": "main.go:27.GetUser",
+  "context": {
+    "source": "database",
+    "user_id": "user-123"
+  }
+}
 ```
 
 The error includes:
 - ✅ Automatic caller information (`main.go:20.GetUser`)
-- ✅ Error code (`USER_404`)
-- ✅ Structured context (user_id, source)
-- ✅ JSON serializable for logging
+- ✅ Error code (`USER_404`) visible in output
+- ✅ Structured context (user_id, source) visible in output
+- ✅ JSON output by default for structured logging
 
 ## ✨ Features
 
@@ -133,6 +144,78 @@ jsonBytes, _ := json.Marshal(err)
 log.Info(string(jsonBytes))
 ```
 
+### 🎨 Output Formats & Verbosity
+
+Errific supports multiple output formats and verbosity levels. **By default, errors output as JSON with all metadata visible**.
+
+```go
+// Default: JSON format with full verbosity (shows all metadata)
+errific.Configure() // or Configure(OutputJSON, VerbosityFull)
+
+err := ErrUserNotFound.
+    WithCode("USER_404").
+    WithContext(errific.Context{"user_id": "user-123"})
+
+fmt.Println(err)
+// Output: {"error":"user not found","code":"USER_404","caller":"main.go:20","context":{"user_id":"user-123"}}
+
+// JSON Pretty format (indented JSON for docs/debugging)
+errific.Configure(OutputJSONPretty)
+fmt.Println(err)
+// Output:
+// {
+//   "error": "user not found",
+//   "code": "USER_404",
+//   "caller": "main.go:20",
+//   "context": {
+//     "user_id": "user-123"
+//   }
+// }
+
+// Pretty format (multi-line, human-readable text)
+errific.Configure(OutputPretty)
+fmt.Println(err)
+// Output:
+//   user not found [main.go:20.GetUser]
+//     code: USER_404
+//     context: map[user_id:user-123]
+
+// Compact format (single-line key=value)
+errific.Configure(OutputCompact)
+fmt.Println(err)
+// Output: user not found [main.go:20] code=USER_404 user_id=user-123
+
+// Minimal verbosity (only message + caller, useful for simple logging)
+errific.Configure(VerbosityMinimal)
+fmt.Println(err)
+// Output (JSON): {"error":"user not found","caller":"main.go:20"}
+
+// Standard verbosity (message + caller + code + category + context)
+errific.Configure(VerbosityStandard)
+fmt.Println(err)
+// Output (JSON): {"error":"user not found","code":"USER_404","caller":"main.go:20","context":{"user_id":"user-123"}}
+
+// Custom verbosity (show only specific fields)
+errific.Configure(VerbosityFull, HideContext, HideMCPData)
+fmt.Println(err)
+// Output (JSON): {"error":"user not found","code":"USER_404","caller":"main.go:20","http_status":404}
+```
+
+**Available output formats:**
+- `OutputJSON` (default) - Compact JSON for structured logging
+- `OutputJSONPretty` - Indented JSON for documentation and debugging
+- `OutputPretty` - Multi-line, human-readable text
+- `OutputCompact` - Single-line key=value pairs
+
+**Available verbosity levels:**
+- `VerbosityFull` (default) - Show all non-empty fields
+- `VerbosityStandard` - Show code, category, context
+- `VerbosityMinimal` - Show only message and caller
+- `VerbosityCustom` - Use with `Show*`/`Hide*` flags for granular control
+
+**Granular field control:**
+`HideCode`, `HideCategory`, `HideContext`, `HideHTTPStatus`, `HideRetryMetadata`, `HideMCPData`, `HideTags`, `HideLabels`, `HideTimestamps`
+
 ### JSON Output
 
 ```json

conf.go

@@ -21,6 +21,19 @@ func Configure(opts ...Option) {
 	c.withStack = false
 	c.trimPrefixes = nil
 	c.trimCWD = false
+	c.outputFormat = OutputJSON
+	c.verbosity = VerbosityFull
+
+	// Default field visibility (used when verbosity is VerbosityFull or VerbosityCustom)
+	c.showCode = true
+	c.showCategory = true
+	c.showContext = true
+	c.showHTTPStatus = true
+	c.showRetryMetadata = true
+	c.showMCPData = true
+	c.showTags = true
+	c.showLabels = true
+	c.showTimestamps = true
 
 	for _, opt := range opts {
 		switch o := opt.(type) {
@@ -38,6 +51,74 @@ func Configure(opts ...Option) {
 
 		case trimCWDOption:
 			c.trimCWD = o
+
+		case outputFormatOption:
+			c.outputFormat = o
+
+		case verbosityOption:
+			c.verbosity = o
+			// Set field visibility based on verbosity level
+			switch o {
+			case VerbosityMinimal:
+				c.showCode = false
+				c.showCategory = false
+				c.showContext = false
+				c.showHTTPStatus = false
+				c.showRetryMetadata = false
+				c.showMCPData = false
+				c.showTags = false
+				c.showLabels = false
+				c.showTimestamps = false
+
+			case VerbosityStandard:
+				c.showCode = true
+				c.showCategory = true
+				c.showContext = true
+				c.showHTTPStatus = false
+				c.showRetryMetadata = false
+				c.showMCPData = false
+				c.showTags = false
+				c.showLabels = false
+				c.showTimestamps = false
+
+			case VerbosityFull:
+				c.showCode = true
+				c.showCategory = true
+				c.showContext = true
+				c.showHTTPStatus = true
+				c.showRetryMetadata = true
+				c.showMCPData = true
+				c.showTags = true
+				c.showLabels = true
+				c.showTimestamps = true
+			}
+
+		case fieldVisibilityOption:
+			// When using field visibility options, automatically switch to VerbosityCustom
+			if c.verbosity != VerbosityCustom {
+				c.verbosity = VerbosityCustom
+			}
+			// Apply the specific field visibility setting
+			switch o.field {
+			case "code":
+				c.showCode = o.show
+			case "category":
+				c.showCategory = o.show
+			case "context":
+				c.showContext = o.show
+			case "http_status":
+				c.showHTTPStatus = o.show
+			case "retry_metadata":
+				c.showRetryMetadata = o.show
+			case "mcp_data":
+				c.showMCPData = o.show
+			case "tags":
+				c.showTags = o.show
+			case "labels":
+				c.showLabels = o.show
+			case "timestamps":
+				c.showTimestamps = o.show
+			}
 		}
 	}
 
@@ -70,6 +151,22 @@ var (
 		// TrimCWD will trim the current working directory from filenames.
 		// Default is false.
 		trimCWD trimCWDOption
+		// Output format: Pretty, JSON, or Compact.
+		// Default is Pretty.
+		outputFormat outputFormatOption
+		// Verbosity controls which fields are shown in Error() output.
+		// Default is VerbosityFull (show all non-empty fields).
+		verbosity verbosityOption
+		// Field visibility flags (used when verbosity is VerbosityCustom)
+		showCode          bool
+		showCategory      bool
+		showContext       bool
+		showHTTPStatus    bool
+		showRetryMetadata bool
+		showMCPData       bool
+		showTags          bool
+		showLabels        bool
+		showTimestamps    bool
 	}
 	cMu sync.RWMutex
 )
@@ -139,6 +236,144 @@ type Option interface {
 	ErrificOption()
 }
 
+// outputFormatOption controls the format of error string output.
+type outputFormatOption int
+
+func (outputFormatOption) ErrificOption() {}
+
+const (
+	// OutputPretty formats errors as human-readable multi-line text with all metadata.
+	//
+	// Example:
+	//   user not found [main.go:20.GetUser]
+	//     code: USER_404
+	//     context: {user_id: user-123, source: database}
+	//     http_status: 400
+	OutputPretty outputFormatOption = iota
+
+	// OutputJSON formats errors as compact JSON.
+	// This is the default.
+	// Useful for structured logging and machine processing.
+	//
+	// Example:
+	//   {"error":"user not found","caller":"main.go:20","code":"USER_404",...}
+	OutputJSON
+
+	// OutputJSONPretty formats errors as indented JSON.
+	// Useful for documentation, debugging, and human-readable JSON output.
+	//
+	// Example:
+	//   {
+	//     "error": "user not found",
+	//     "code": "USER_404",
+	//     "caller": "main.go:20"
+	//   }
+	OutputJSONPretty
+
+	// OutputCompact formats errors as single-line text with key=value pairs.
+	// Useful for log aggregation systems.
+	//
+	// Example:
+	//   user not found [main.go:20] code=USER_404 user_id=user-123 http_status=400
+	OutputCompact
+)
+
+// verbosityOption controls which fields are included in Error() output.
+type verbosityOption int
+
+func (verbosityOption) ErrificOption() {}
+
+const (
+	// VerbosityMinimal shows only the error message and caller.
+	//
+	// Example:
+	//   user not found [main.go:20.GetUser]
+	VerbosityMinimal verbosityOption = iota
+
+	// VerbosityStandard shows message, caller, code, category, and context.
+	// Good balance for most applications.
+	//
+	// Example:
+	//   user not found [main.go:20.GetUser]
+	//     code: USER_404
+	//     category: validation
+	//     context: {user_id: user-123}
+	VerbosityStandard
+
+	// VerbosityFull shows all non-empty fields (default).
+	// Recommended for debugging and development.
+	//
+	// Example:
+	//   user not found [main.go:20.GetUser]
+	//     code: USER_404
+	//     category: validation
+	//     context: {user_id: user-123, source: database}
+	//     http_status: 400
+	//     retryable: true
+	//     correlation_id: trace-123
+	//     help: Check if user exists
+	VerbosityFull
+
+	// VerbosityCustom allows fine-grained control via individual field flags.
+	// Use with Show* and Hide* options.
+	VerbosityCustom
+)
+
+// Field visibility options for VerbosityCustom.
+type fieldVisibilityOption struct {
+	field string
+	show  bool
+}
+
+func (fieldVisibilityOption) ErrificOption() {}
+
+var (
+	// ShowCode includes error code in output.
+	ShowCode = fieldVisibilityOption{field: "code", show: true}
+	// HideCode excludes error code from output.
+	HideCode = fieldVisibilityOption{field: "code", show: false}
+
+	// ShowCategory includes error category in output.
+	ShowCategory = fieldVisibilityOption{field: "category", show: true}
+	// HideCategory excludes error category from output.
+	HideCategory = fieldVisibilityOption{field: "category", show: false}
+
+	// ShowContext includes structured context in output.
+	ShowContext = fieldVisibilityOption{field: "context", show: true}
+	// HideContext excludes structured context from output.
+	HideContext = fieldVisibilityOption{field: "context", show: false}
+
+	// ShowHTTPStatus includes HTTP status code in output.
+	ShowHTTPStatus = fieldVisibilityOption{field: "http_status", show: true}
+	// HideHTTPStatus excludes HTTP status code from output.
+	HideHTTPStatus = fieldVisibilityOption{field: "http_status", show: false}
+
+	// ShowRetryMetadata includes retry information (retryable, retry_after, max_retries) in output.
+	ShowRetryMetadata = fieldVisibilityOption{field: "retry_metadata", show: true}
+	// HideRetryMetadata excludes retry information from output.
+	HideRetryMetadata = fieldVisibilityOption{field: "retry_metadata", show: false}
+
+	// ShowMCPData includes MCP-related fields (correlation_id, help, suggestion, etc.) in output.
+	ShowMCPData = fieldVisibilityOption{field: "mcp_data", show: true}
+	// HideMCPData excludes MCP-related fields from output.
+	HideMCPData = fieldVisibilityOption{field: "mcp_data", show: false}
+
+	// ShowTags includes semantic tags in output.
+	ShowTags = fieldVisibilityOption{field: "tags", show: true}
+	// HideTags excludes semantic tags from output.
+	HideTags = fieldVisibilityOption{field: "tags", show: false}
+
+	// ShowLabels includes key-value labels in output.
+	ShowLabels = fieldVisibilityOption{field: "labels", show: true}
+	// HideLabels excludes key-value labels from output.
+	HideLabels = fieldVisibilityOption{field: "labels", show: false}
+
+	// ShowTimestamps includes timestamp and duration in output.
+	ShowTimestamps = fieldVisibilityOption{field: "timestamps", show: true}
+	// HideTimestamps excludes timestamp and duration from output.
+	HideTimestamps = fieldVisibilityOption{field: "timestamps", show: false}
+)
+
 var root string
 var goroot string