Merge pull request #21 from alchemy/fix_gopath_callerframe

Two fixes

builder.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"os"
 	"path/filepath"
 	"strings"
 
@@ -14,7 +13,7 @@ import (
 func BuildDoc(r chi.Routes) (Doc, error) {
 	d := Doc{}
 
-	goPath := os.Getenv("GOPATH")
+	goPath := getGoPath()
 	if goPath == "" {
 		return d, errors.New("docgen: unable to determine your $GOPATH")
 	}
@@ -83,7 +82,7 @@ func buildDocRouter(r chi.Routes) DocRouter {
 func buildFuncInfo(i interface{}) FuncInfo {
 	fi := FuncInfo{}
 	frame := getCallerFrame(i)
-	goPathSrc := filepath.Join(os.Getenv("GOPATH"), "src")
+	goPathSrc := filepath.Join(getGoPath(), "src")
 
 	if frame == nil {
 		fi.Unresolvable = true

funcinfo.go

@@ -3,7 +3,6 @@ package docgen
 import (
 	"go/parser"
 	"go/token"
-	"os"
 	"path/filepath"
 	"reflect"
 	"runtime"
@@ -23,7 +22,7 @@ type FuncInfo struct {
 func GetFuncInfo(i interface{}) FuncInfo {
 	fi := FuncInfo{}
 	frame := getCallerFrame(i)
-	goPathSrc := filepath.Join(os.Getenv("GOPATH"), "src")
+	goPathSrc := filepath.Join(getGoPath(), "src")
 
 	if frame == nil {
 		fi.Unresolvable = true
@@ -67,7 +66,11 @@ func GetFuncInfo(i interface{}) FuncInfo {
 }
 
 func getCallerFrame(i interface{}) *runtime.Frame {
-	pc := reflect.ValueOf(i).Pointer()
+	value := reflect.ValueOf(i)
+	if value.Kind() != reflect.Func {
+		return nil
+	}
+	pc := value.Pointer()
 	frames := runtime.CallersFrames([]uintptr{pc})
 	if frames == nil {
 		return nil

util.go

@@ -1,5 +1,10 @@
 package docgen
 
+import (
+	"go/build"
+	"os"
+)
+
 func copyDocRouter(dr DocRouter) DocRouter {
 	var cloneRouter func(dr DocRouter) DocRouter
 	var cloneRoutes func(drt DocRoutes) DocRoutes
@@ -35,3 +40,11 @@ func copyDocRouter(dr DocRouter) DocRouter {
 
 	return cloneRouter(dr)
 }
+
+func getGoPath() string {
+	goPath := os.Getenv("GOPATH")
+	if goPath == "" {
+		goPath = build.Default.GOPATH
+	}
+	return goPath
+}