Be more judicious about selecting named interfaces

.github/workflows/go.yml

@@ -27,10 +27,11 @@ jobs:
         uses: shogo82148/actions-goveralls@v1
         with:
           path-to-profile: cover.out
+        continue-on-error: true
 
       - name: Modver
         if: ${{ github.event_name == 'pull_request' }}
-        uses: bobg/modver@v2.7.0
+        uses: bobg/modver@v2.12.1
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           pull_request_url: https://github.com/${{ github.repository }}/pull/${{ github.event.number }}

Readme.md

@@ -3,7 +3,7 @@
 [![Go Reference](https://pkg.go.dev/badge/github.com/bobg/decouple.svg)](https://pkg.go.dev/github.com/bobg/decouple)
 [![Go Report Card](https://goreportcard.com/badge/github.com/bobg/decouple)](https://goreportcard.com/report/github.com/bobg/decouple)
 [![Tests](https://github.com/bobg/decouple/actions/workflows/go.yml/badge.svg)](https://github.com/bobg/decouple/actions/workflows/go.yml)
-[![Coverage Status](https://coveralls.io/repos/github/bobg/decouple/badge.svg?branch=main)](https://coveralls.io/github/bobg/decouple?branch=main)
+[![Coverage Status](https://coveralls.io/repos/github.com/bobg/decouple/badge.svg?branch=main)](https://coveralls.io/github.com/bobg/decouple?branch=main)
 [![Mentioned in Awesome Go](https://awesome.re/mentioned-badge.svg)](https://github.com/avelino/awesome-go)
 
 This is decouple,
@@ -135,7 +135,8 @@ The same report with `-json` specified looks like this:
       "Methods": [
         "Write"
       ],
-      "InterfaceName": "io.Writer"
+      "InterfaceName": "Writer",
+      "InterfacePkg": "io"
     }
   ]
 }

_testdata/foo.go

@@ -7,6 +7,12 @@ import (
 	"os"
 )
 
+// This named type should never be suggested,
+// since it is superseded by an identical one in the stdlib.
+type JankyReader interface {
+	Read([]byte) (int, error)
+}
+
 // {"r": {"Read": "func([]byte) (int, error)"}}
 // {"r": "io.Reader"}
 func F1(r *os.File, n int) ([]byte, error) {
@@ -274,7 +280,6 @@ func F34(r *os.File, ch chan<- *os.File) ([]byte, error) {
 }
 
 // {"x": {"foo": "func()"}}
-// {"x": ""}
 func F35(x interface {
 	foo()
 	bar()

_testdata/go.mod

@@ -1,3 +1,3 @@
-module m
+module github.com/bobg/decouple/testdata
 
-go 1.19
+go 1.23

cmd/decouple/decouple_test.go

@@ -5,10 +5,11 @@ import (
 	"encoding/json"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"strings"
 	"testing"
 
-	"github.com/bobg/go-generics/v3/iter"
+	"github.com/bobg/seqs"
 )
 
 func TestRunJSON(t *testing.T) {
@@ -33,7 +34,7 @@ func TestRunJSON(t *testing.T) {
 	want := []jtuple{{
 		PackageName: "main",
 		FileName:    "main.go",
-		Line:        100,
+		Line:        106,
 		Column:      6,
 		FuncName:    "showJSON",
 		Params: []jparam{{
@@ -55,8 +56,9 @@ func TestRunPlain(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	lines, err := iter.ToSlice(iter.Lines(buf))
-	if err != nil {
+	linesSeq, errptr := seqs.Lines(buf)
+	lines := slices.Collect(linesSeq)
+	if err := *errptr; err != nil {
 		t.Fatal(err)
 	}
 

cmd/decouple/main.go

@@ -5,11 +5,13 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"maps"
 	"os"
+	"slices"
 	"sort"
+	"strings"
 
 	"github.com/bobg/errors"
-	"github.com/bobg/go-generics/v3/maps"
 
 	"github.com/bobg/decouple"
 )
@@ -37,7 +39,7 @@ func run(w io.Writer, verbose, doJSON bool, args []string) error {
 	case 1:
 		dir = args[0]
 	default:
-		return fmt.Errorf("Usage: %s [-v] [-json] [DIR]", os.Args[0])
+		return fmt.Errorf("usage: %s [-v] [-json] [DIR]", os.Args[0])
 	}
 
 	checker, err := decouple.NewCheckerFromDir(dir)
@@ -70,7 +72,7 @@ func run(w io.Writer, verbose, doJSON bool, args []string) error {
 	for _, tuple := range tuples {
 		var showedFuncName bool
 
-		params := maps.Keys(tuple.M)
+		params := slices.Collect(maps.Keys(tuple.M))
 		sort.Strings(params)
 		for _, param := range params {
 			mm := tuple.M[param]
@@ -83,12 +85,16 @@ func run(w io.Writer, verbose, doJSON bool, args []string) error {
 				showedFuncName = true
 			}
 
-			if intfName := checker.NameForMethods(mm); intfName != "" {
-				fmt.Fprintf(w, "    %s: %s\n", param, intfName)
+			if pkg, intfName := checker.NameForMethods(mm); intfName != "" {
+				pkgpath := pkg.PkgPath
+				if strings.ContainsAny(pkgpath, "./") {
+					pkgpath = fmt.Sprintf(`"%s"`, pkgpath)
+				}
+				fmt.Fprintf(w, "    %s: %s.%s\n", param, pkgpath, intfName)
 				continue
 			}
 
-			methods := maps.Keys(tuple.M[param])
+			methods := slices.Collect(maps.Keys(tuple.M[param]))
 			sort.Strings(methods)
 			fmt.Fprintf(w, "    %s: %v\n", param, methods)
 		}
@@ -116,10 +122,11 @@ func showJSON(w io.Writer, checker decouple.Checker, tuples []decouple.Tuple) er
 			}
 			jp := jparam{
 				Name:    param,
-				Methods: maps.Keys(mm),
+				Methods: slices.Collect(maps.Keys(mm)),
 			}
 			sort.Strings(jp.Methods)
-			if intfName := checker.NameForMethods(mm); intfName != "" {
+			if pkg, intfName := checker.NameForMethods(mm); intfName != "" {
+				jp.InterfacePkg = pkg.PkgPath
 				jp.InterfaceName = intfName
 			}
 			jt.Params = append(jt.Params, jp)
@@ -149,5 +156,6 @@ type jtuple struct {
 type jparam struct {
 	Name          string
 	Methods       []string `json:",omitempty"`
+	InterfacePkg  string   `json:",omitempty"`
 	InterfaceName string   `json:",omitempty"`
 }

debug.go

@@ -11,9 +11,9 @@ func (a *analyzer) debugf(format string, args ...any) {
 		return
 	}
 	s := fmt.Sprintf(format, args...)
-	strings.TrimRight(s, "\r\n")
+	s = strings.TrimRight(s, "\r\n")
 	if a.level > 0 {
-		fmt.Fprintf(os.Stderr, strings.Repeat("  ", a.level))
+		fmt.Fprint(os.Stderr, strings.Repeat("  ", a.level))
 	}
 	fmt.Fprintln(os.Stderr, s)
 }