feat: add SuggestedFixes for --fix support

analyzer.go

@@ -1,6 +1,7 @@
 package recvcheck
 
 import (
+	"fmt"
 	"go/ast"
 
 	"golang.org/x/tools/go/analysis"
@@ -87,13 +88,28 @@ func (r *analyzer) run(pass *analysis.Pass) (any, error) {
 		if isStar {
 			st.starUsed = true
 		} else {
-			st.typeUsed = true
+			st.valueRecvTypes = append(st.valueRecvTypes, recv)
 		}
 	})
 
 	for recv, st := range structs {
-		if st.starUsed && st.typeUsed {
-			pass.Reportf(pass.Pkg.Scope().Lookup(recv).Pos(), "the methods of %q use pointer receiver and non-pointer receiver.", recv)
+		if st.starUsed && len(st.valueRecvTypes) > 0 {
+			edits := make([]analysis.TextEdit, len(st.valueRecvTypes))
+			for i, ident := range st.valueRecvTypes {
+				edits[i] = analysis.TextEdit{
+					Pos:     ident.Pos(),
+					End:     ident.Pos(),
+					NewText: []byte("*"),
+				}
+			}
+			pass.Report(analysis.Diagnostic{
+				Pos:     pass.Pkg.Scope().Lookup(recv).Pos(),
+				Message: fmt.Sprintf("the methods of %q use pointer receiver and non-pointer receiver.", recv),
+				SuggestedFixes: []analysis.SuggestedFix{{
+					Message:   fmt.Sprintf("use pointer receiver for %q", recv),
+					TextEdits: edits,
+				}},
+			})
 		}
 	}
 
@@ -116,8 +132,8 @@ func (r *analyzer) isExcluded(recv *ast.Ident, f *ast.FuncDecl) bool {
 }
 
 type structType struct {
-	starUsed bool
-	typeUsed bool
+	starUsed       bool
+	valueRecvTypes []*ast.Ident
 }
 
 func recvTypeIdent(r ast.Expr) (*ast.Ident, bool) {

analyzer_test.go

@@ -38,7 +38,7 @@ func TestAnalyzer(t *testing.T) {
 		t.Run(test.desc, func(t *testing.T) {
 			a := recvcheck.NewAnalyzer(test.settings)
 
-			analysistest.Run(t, analysistest.TestData(), a, test.desc)
+			analysistest.RunWithSuggestedFixes(t, analysistest.TestData(), a, test.desc)
 		})
 	}
 }

testdata/src/basic/rpc.go.golden

@@ -0,0 +1,33 @@
+package basic
+
+import (
+	"time"
+)
+
+type RPC struct { // want `the methods of "RPC" use pointer receiver and non-pointer receiver.`
+	result int
+	done   chan struct{}
+}
+
+func (rpc *RPC) compute() {
+	time.Sleep(time.Second) // strenuous computation intensifies
+	rpc.result = 42
+	close(rpc.done)
+}
+
+func (*RPC) version() int {
+	return 1 // never going to need to change this
+}
+
+// Following main function cause data race error
+// reference: https://dave.cheney.net/2015/11/18/wednesday-pop-quiz-spot-the-race
+// func main() {
+// 	rpc := &RPC{done: make(chan struct{})}
+//
+// 	go rpc.compute()         // kick off computation in the background
+// 	version := rpc.version() // grab some other information while we're waiting
+// 	<-rpc.done               // wait for computation to finish
+// 	result := rpc.result
+//
+// 	fmt.Printf("RPC computation complete, result: %d, version: %d\n", result, version)
+// }

testdata/src/disablebuiltin/binary.go.golden

@@ -0,0 +1,11 @@
+package disablebuiltin
+
+type Binary struct{} // want `the methods of "Binary" use pointer receiver and non-pointer receiver.`
+
+func (b *Binary) MarshalBinary() ([]byte, error) {
+	panic("not implemented")
+}
+
+func (b *Binary) UnmarshalBinary(data []byte) error {
+	panic("not implemented")
+}

testdata/src/disablebuiltin/gob.go.golden

@@ -0,0 +1,11 @@
+package disablebuiltin
+
+type Gob struct{} // want `the methods of "Gob" use pointer receiver and non-pointer receiver.`
+
+func (g *Gob) GobEncode() ([]byte, error) {
+	panic("not implemented")
+}
+
+func (g *Gob) GobDecode(data []byte) error {
+	panic("not implemented")
+}

testdata/src/disablebuiltin/json.go.golden

@@ -0,0 +1,11 @@
+package disablebuiltin
+
+type JSON struct{} // want `the methods of "JSON" use pointer receiver and non-pointer receiver.`
+
+func (j *JSON) MarshalJSON() ([]byte, error) {
+	panic("not implemented")
+}
+
+func (j *JSON) UnmarshalJSON(b []byte) error {
+	panic("not implemented")
+}

testdata/src/disablebuiltin/text.go.golden

@@ -0,0 +1,11 @@
+package disablebuiltin
+
+type Text struct{} // want `the methods of "Text" use pointer receiver and non-pointer receiver.`
+
+func (t *Text) MarshalText() ([]byte, error) {
+	panic("not implemented")
+}
+
+func (t *Text) UnmarshalText(b []byte) error {
+	panic("not implemented")
+}

testdata/src/disablebuiltin/xml.go.golden

@@ -0,0 +1,13 @@
+package disablebuiltin
+
+import "encoding/xml"
+
+type XML struct{} // want `the methods of "XML" use pointer receiver and non-pointer receiver.`
+
+func (x *XML) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	panic("not implemented")
+}
+
+func (x *XML) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	panic("not implemented")
+}

testdata/src/disablebuiltin/yaml.go.golden

@@ -0,0 +1,13 @@
+package disablebuiltin
+
+type Node struct{}
+
+type YAML struct{} // want `the methods of "YAML" use pointer receiver and non-pointer receiver.`
+
+func (j *YAML) MarshalYAML() (any, error) {
+	panic("not implemented")
+}
+
+func (j *YAML) UnmarshalYAML(value *Node) error {
+	panic("not implemented")
+}