internal/lsp: add fields to anonymous struct info

Anonymous struct quick fixes should provide more information on which struct they will fill. This adds the first fields of an anonymous struct to the fill title. Updates golang/go#48563 Change-Id: I42cee2e8b1b9405ac2e2e8cfb8deb2c7710c3056 Reviewed-on: https://go-review.googlesource.com/c/tools/+/351591 Trust: Suzy Mueller <[email protected]> Run-TryBot: Suzy Mueller <[email protected]> gopls-CI: kokoro <[email protected]> TryBot-Result: Go Bot <[email protected]> Reviewed-by: Rebecca Stambler <[email protected]>
golang · Sep 24, 2021 · ba6b94c · ba6b94c
1 parent 939195f
commit ba6b94c
Showing 1 changed file with 18 additions and 1 deletion.
diff --git a/internal/lsp/analysis/fillstruct/fillstruct.go b/internal/lsp/analysis/fillstruct/fillstruct.go
@@ -13,6 +13,7 @@ import (
 	"go/format"
 	"go/token"
 	"go/types"
+	"strings"
 	"unicode"
 
 	"golang.org/x/tools/go/analysis"
@@ -87,13 +88,15 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		}
 
 		var fillable bool
+		var fillableFields []string
 		for i := 0; i < fieldCount; i++ {
 			field := obj.Field(i)
 			// Ignore fields that are not accessible in the current package.
 			if field.Pkg() != nil && field.Pkg() != pass.Pkg && !field.Exported() {
 				continue
 			}
 			fillable = true
+			fillableFields = append(fillableFields, fmt.Sprintf("%s: %s", field.Name(), field.Type().String()))
 		}
 		if !fillable {
 			return
@@ -105,7 +108,21 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		case *ast.SelectorExpr:
 			name = fmt.Sprintf("%s.%s", typ.X, typ.Sel.Name)
 		default:
-			name = "anonymous struct"
+			totalFields := len(fillableFields)
+			maxLen := 20
+			// Find the index to cut off printing of fields.
+			var i, fieldLen int
+			for i = range fillableFields {
+				if fieldLen > maxLen {
+					break
+				}
+				fieldLen += len(fillableFields[i])
+			}
+			fillableFields = fillableFields[:i]
+			if i < totalFields {
+				fillableFields = append(fillableFields, "...")
+			}
+			name = fmt.Sprintf("anonymous struct { %s }", strings.Join(fillableFields, ", "))
 		}
 		pass.Report(analysis.Diagnostic{
 			Message: fmt.Sprintf("Fill %s", name),