gopls/internal/analysis/modernize: don't offer a fix when initialization statement is not empty

Fixes golang/go#73547

Change-Id: I878f7ab71c1dce896f5eef7fb319cf99b2394f88
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669055
Reviewed-by: Alan Donovan <[email protected]>
Auto-Submit: Alan Donovan <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: cuishuang

gopls/internal/analysis/modernize/stringscutprefix.go

@@ -59,7 +59,8 @@ func stringscutprefix(pass *analysis.Pass) {
 			ifStmt := curIfStmt.Node().(*ast.IfStmt)
 
 			// pattern1
-			if call, ok := ifStmt.Cond.(*ast.CallExpr); ok && len(ifStmt.Body.List) > 0 {
+			if call, ok := ifStmt.Cond.(*ast.CallExpr); ok && ifStmt.Init == nil && len(ifStmt.Body.List) > 0 {
+
 				obj := typeutil.Callee(info, call)
 				if !analysisinternal.IsFunctionNamed(obj, "strings", "HasPrefix") &&
 					!analysisinternal.IsFunctionNamed(obj, "bytes", "HasPrefix") {

gopls/internal/analysis/modernize/testdata/src/stringscutprefix/stringscutprefix.go

@@ -59,6 +59,10 @@ func _() {
 		a := strings.TrimPrefix(s, pre) // noop, as the argument isn't the same
 		_ = a
 	}
+	if s1 := s; strings.HasPrefix(s1, pre) {
+		a := strings.TrimPrefix(s1, pre) // noop, as IfStmt.Init is present
+		_ = a
+	}
 }
 
 var value0 string

gopls/internal/analysis/modernize/testdata/src/stringscutprefix/stringscutprefix.go.golden

@@ -59,6 +59,10 @@ func _() {
 		a := strings.TrimPrefix(s, pre) // noop, as the argument isn't the same
 		_ = a
 	}
+	if s1 := s; strings.HasPrefix(s1, pre) {
+		a := strings.TrimPrefix(s1, pre) // noop, as IfStmt.Init is present
+		_ = a
+	}
 }
 
 var value0 string