API docs

vendor/github.com/go-chi/docgen/funcinfo.go

@@ -0,0 +1,116 @@
+package docgen
+
+import (
+	"go/parser"
+	"go/token"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"strings"
+)
+
+type FuncInfo struct {
+	Pkg          string `json:"pkg"`
+	Func         string `json:"func"`
+	Comment      string `json:"comment"`
+	File         string `json:"file,omitempty"`
+	Line         int    `json:"line,omitempty"`
+	Anonymous    bool   `json:"anonymous,omitempty"`
+	Unresolvable bool   `json:"unresolvable,omitempty"`
+}
+
+func GetFuncInfo(i interface{}) FuncInfo {
+	fi := FuncInfo{}
+	frame := getCallerFrame(i)
+	goPathSrc := filepath.Join(getGoPath(), "src")
+
+	if frame == nil {
+		fi.Unresolvable = true
+		return fi
+	}
+
+	pkgName := getPkgName(frame.File)
+	if pkgName == "chi" {
+		fi.Unresolvable = true
+	}
+	funcPath := frame.Func.Name()
+
+	idx := strings.Index(funcPath, "/"+pkgName)
+	if idx > 0 {
+		fi.Pkg = funcPath[:idx+1+len(pkgName)]
+		fi.Func = funcPath[idx+2+len(pkgName):]
+	} else {
+		fi.Func = funcPath
+	}
+
+	if strings.Index(fi.Func, ".func") > 0 {
+		fi.Anonymous = true
+	}
+
+	fi.File = frame.File
+	fi.Line = frame.Line
+	if filepath.HasPrefix(fi.File, goPathSrc) {
+		fi.File = fi.File[len(goPathSrc)+1:]
+	}
+
+	// Check if file info is unresolvable
+	if strings.Index(funcPath, pkgName) < 0 {
+		fi.Unresolvable = true
+	}
+
+	if !fi.Unresolvable {
+		fi.Comment = getFuncComment(frame.File, frame.Line)
+	}
+
+	return fi
+}
+
+func getCallerFrame(i interface{}) *runtime.Frame {
+	value := reflect.ValueOf(i)
+	if value.Kind() != reflect.Func {
+		return nil
+	}
+	pc := value.Pointer()
+	frames := runtime.CallersFrames([]uintptr{pc})
+	if frames == nil {
+		return nil
+	}
+	frame, _ := frames.Next()
+	if frame.Entry == 0 {
+		return nil
+	}
+	return &frame
+}
+
+func getPkgName(file string) string {
+	fset := token.NewFileSet()
+	astFile, err := parser.ParseFile(fset, file, nil, parser.PackageClauseOnly)
+	if err != nil {
+		return ""
+	}
+	if astFile.Name == nil {
+		return ""
+	}
+	return astFile.Name.Name
+}
+
+func getFuncComment(file string, line int) string {
+	fset := token.NewFileSet()
+
+	astFile, err := parser.ParseFile(fset, file, nil, parser.ParseComments)
+	if err != nil {
+		return ""
+	}
+
+	if len(astFile.Comments) == 0 {
+		return ""
+	}
+
+	for _, cmt := range astFile.Comments {
+		if fset.Position(cmt.End()).Line+1 == line {
+			return cmt.Text()
+		}
+	}
+
+	return ""
+}