linters: add autofix for httpstatus

pkg/httpstatus/analyzer.go

@@ -2,9 +2,11 @@
 package httpstatus
 
 import (
+	"fmt"
 	"go/ast"
 	"go/constant"
 	"go/types"
+	"strconv"
 	"strings"
 
 	"golang.org/x/tools/go/analysis"
@@ -62,7 +64,19 @@ func NewAnalyzer(settings Settings) *analysis.Analyzer {
 					return
 				}
 
-				pass.Reportf(node.Pos(), "HTTP status code %d should use its integer literal", code)
+				pass.Report(analysis.Diagnostic{
+					Pos:     node.Pos(),
+					End:     node.End(),
+					Message: fmt.Sprintf("HTTP status code %d should use its integer literal", code),
+					SuggestedFixes: []analysis.SuggestedFix{{
+						Message: "Use the integer literal",
+						TextEdits: []analysis.TextEdit{{
+							Pos:     node.Pos(),
+							End:     node.End(),
+							NewText: []byte(strconv.Itoa(code)),
+						}},
+					}},
+				})
 			}
 
 			// Disallows sending non-typical response statuses

pkg/httpstatus/analyzer_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestAnalyzer(t *testing.T) {
-	analysistest.Run(t, analysistest.TestData(), httpstatus.Analyzer, "default")
+	analysistest.RunWithSuggestedFixes(t, analysistest.TestData(), httpstatus.Analyzer, "default")
 }
 
 func TestAnalyzerWithSettings(t *testing.T) {
@@ -18,5 +18,5 @@ func TestAnalyzerWithSettings(t *testing.T) {
 		IsRestricted:       true,
 	})
 
-	analysistest.Run(t, analysistest.TestData(), analyzer, "configured")
+	analysistest.RunWithSuggestedFixes(t, analysistest.TestData(), analyzer, "configured")
 }

pkg/httpstatus/testdata/src/configured/configured.go.golden

@@ -0,0 +1,29 @@
+package configured
+
+import "net/http"
+
+const created = 201 // want `HTTP status code 201 should use its integer literal`
+const ok = http.StatusOK
+
+func response(w http.ResponseWriter, r *http.Request, code int) {
+	http.Error(w, "teapot", 418) // want `non-typical HTTP status code 418 is not allowed`
+	http.Error(w, "created", 201)
+	http.Error(w, "variable", code)
+
+	w.WriteHeader(200) // want `non-typical HTTP status code 200 is not allowed`
+	w.WriteHeader(code)
+	http.ResponseWriter.WriteHeader(w, 400) // want `non-typical HTTP status code 400 is not allowed`
+
+	http.NotFound(w, r)
+	_, _ = w.Write([]byte("response"))
+	http.Redirect(w, r, "/moved", 301)
+	http.Redirect(w, r, "/created", 201) // want `HTTP status code 201 should use its integer literal`
+}
+
+type unrelatedWriter struct{}
+
+func (unrelatedWriter) WriteHeader(int) {}
+
+func unrelated(writer unrelatedWriter) {
+	writer.WriteHeader(418)
+}

pkg/httpstatus/testdata/src/default/default.go.golden

@@ -0,0 +1,22 @@
+package cases
+
+import "net/http"
+
+const ok = 200 // want `HTTP status code 200 should use its integer literal`
+const teapot = http.StatusTeapot
+
+func response(w http.ResponseWriter, r *http.Request, code int) {
+	_ = 404 // want `HTTP status code 404 should use its integer literal`
+
+	http.Error(w, "bad request", 400) // want `HTTP status code 400 should use its integer literal`
+	http.Error(w, "teapot", http.StatusTeapot)
+	http.Error(w, "created", 201)
+	w.WriteHeader(504) // want `HTTP status code 504 should use its integer literal`
+	w.WriteHeader(code)
+
+	http.NotFound(w, r)
+	_, _ = w.Write([]byte("response"))
+
+	http.Redirect(w, r, "/login", 302) // want `HTTP status code 302 should use its integer literal`
+	http.Redirect(w, r, "/other", http.StatusMovedPermanently)
+}