test: add unit test for catching cyclic verbs (#4733)

closes #4633

go-runtime/compile/build.go

@@ -912,7 +912,7 @@ func (b *mainDeploymentContextBuilder) visit(
 			}
 			err := b.visit(ctx, m, resolved, parents)
 			if err != nil {
-				return fmt.Errorf("failed to visit children of %s: %w", n, err)
+				return err //nolint:wrapcheck
 			}
 			return next()
 		default:
@@ -948,7 +948,7 @@ func (b *mainDeploymentContextBuilder) visit(
 		return next()
 	})
 	if err != nil {
-		return fmt.Errorf("failed to build main module context: %w", err)
+		return err //nolint:wrapcheck
 	}
 	return nil
 }

go-runtime/compile/build_test.go

@@ -3,12 +3,17 @@ package compile
 import (
 	"os"
 	"path/filepath"
+	stdslices "slices"
 	"testing"
 
 	"github.com/alecthomas/assert/v2"
 	"github.com/alecthomas/types/optional"
 
 	"github.com/block/ftl/common/schema"
+	"github.com/block/ftl/common/slices"
+	"github.com/block/ftl/common/strcase"
+	goschema "github.com/block/ftl/go-runtime/schema"
+	"github.com/block/ftl/go-runtime/schema/common"
 	"github.com/block/ftl/internal/watch"
 )
 
@@ -105,3 +110,36 @@ go 1.23.0
 	_, _, err = updateGoModule(goModPath, "mymodule", optional.None[watch.ModifyFilesTransaction]())
 	assert.Contains(t, err.Error(), "module name mismatch: expected 'ftl/mymodule' but got 'ftl/wrongname'")
 }
+
+func TestCylicVerbs(t *testing.T) {
+	module, err := schema.ParseModuleString("", `
+module cyclic {
+  verb a(Unit) Unit
+    +calls cyclic.b
+
+  verb b(Unit) Unit
+    +calls cyclic.c
+
+  verb c(Unit) Unit
+    +calls cyclic.a
+}
+	`)
+	assert.NoError(t, err)
+	verbDecls := stdslices.Collect(slices.FilterVariants[*schema.Verb](module.Decls))
+	_, err = buildMainDeploymentContext(&schema.Schema{}, goschema.Result{
+		Module: module,
+		VerbResourceParamOrder: map[*schema.Verb][]common.VerbResourceParam{
+			verbDecls[0]: {},
+			verbDecls[1]: {},
+			verbDecls[2]: {},
+		},
+		NativeNames: goschema.NativeNames{
+			verbDecls[0]: "ftl/cyclic." + strcase.ToUpperCamel(module.Decls[0].GetName()),
+			verbDecls[1]: "ftl/cyclic." + strcase.ToUpperCamel(module.Decls[1].GetName()),
+			verbDecls[2]: "ftl/cyclic." + strcase.ToUpperCamel(module.Decls[2].GetName()),
+		},
+	},
+		"", "projectname", nil, nil)
+
+	assert.EqualError(t, err, "cyclic references are not allowed: cyclic.a refers to cyclic.b refers to cyclic.c refers to cyclic.a")
+}

go-runtime/schema/schema_integration_test.go

@@ -513,9 +513,6 @@ func testParsedirectives(t *testing.T) {
 }
 
 func testErrorReporting(t *testing.T) {
-}
-
-func TestErrorReporting(t *testing.T) {
 	if testing.Short() {
 		t.SkipNow()
 	}