pkg/aflow: add DoWhile loop action

DoWhile represents "do { body } while (cond)" loop.
See added test for an example.

1 files changed, 96 insertions, 0 deletions

diff --git a/pkg/aflow/loop_test.go b/pkg/aflow/loop_test.go
new file mode 100644
index 000000000..e68191c2b
--- /dev/null
+++ b/pkg/aflow/loop_test.go
@@ -0,0 +1,96 @@
+// Copyright 2026 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package aflow
+
+import (
+	"testing"
+)
+
+func TestDoWhile(t *testing.T) {
+	type inputs struct {
+		Bug string
+	}
+	type outputs struct {
+		Diff string
+	}
+	type patchArgs struct {
+		Bug       string
+		Diff      string
+		TestError string
+	}
+	type patchResults struct {
+		Patch string
+	}
+	type testArgs struct {
+		Patch string
+	}
+	type testResults struct {
+		Diff      string
+		TestError string
+	}
+	iter := 0
+	testFlow[inputs, outputs](t, map[string]any{"Bug": "bug"}, map[string]any{"Diff": "diff"},
+		&DoWhile{
+			Do: Pipeline(
+				NewFuncAction("patch-generator", func(ctx *Context, args patchArgs) (patchResults, error) {
+					iter++
+					if iter <= 2 {
+						return patchResults{"bad"}, nil
+					}
+					return patchResults{"good"}, nil
+				}),
+				NewFuncAction("patch-tester", func(ctx *Context, args testArgs) (testResults, error) {
+					if args.Patch == "bad" {
+						return testResults{TestError: "error"}, nil
+					}
+					return testResults{Diff: "diff"}, nil
+				}),
+			),
+			While: "TestError",
+		},
+		nil,
+	)
+}
+
+func TestDoWhileErrors(t *testing.T) {
+	testRegistrationError[struct{}, struct{}](t,
+		"flow test: action body: no input Missing, available inputs: []",
+		Pipeline(
+			&DoWhile{
+				Do: NewFuncAction("body", func(ctx *Context, args struct {
+					Missing string
+				}) (struct{}, error) {
+					return struct{}{}, nil
+				}),
+				While: "Condition",
+			},
+		))
+
+	testRegistrationError[struct{ Input string }, struct{}](t,
+		"flow test: action DoWhile: While must not be empty",
+		Pipeline(
+			&DoWhile{
+				Do: NewFuncAction("body", func(ctx *Context, args struct {
+					Input string
+				}) (struct{}, error) {
+					return struct{}{}, nil
+				}),
+			},
+		))
+
+	type output struct {
+		Output1 string
+		Output2 string
+	}
+	testRegistrationError[struct{}, struct{}](t,
+		"flow test: action body: output Output2 is unused",
+		Pipeline(
+			&DoWhile{
+				Do: NewFuncAction("body", func(ctx *Context, args struct{}) (output, error) {
+					return output{}, nil
+				}),
+				While: "Output1",
+			},
+		))
+}