From b865882831386902279da8d025bc2df1437f70d8 Mon Sep 17 00:00:00 2001
From: Matt Toohey <mtoohey@block.xyz>
Date: Thu, 30 Jan 2025 15:17:19 +1100
Subject: [PATCH] fix: add warning if build or deploy command finds no modules
 (#4239)

fixes https://github.com/block/ftl/issues/4214
---
 cmd/ftl/cmd_build.go  | 6 ++++++
 cmd/ftl/cmd_deploy.go | 7 ++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/cmd/ftl/cmd_build.go b/cmd/ftl/cmd_build.go
index 870c0d1684..c8a739ce44 100644
--- a/cmd/ftl/cmd_build.go
+++ b/cmd/ftl/cmd_build.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/block/ftl/backend/protos/xyz/block/ftl/v1/ftlv1connect"
 	"github.com/block/ftl/internal/buildengine"
+	"github.com/block/ftl/internal/log"
 	"github.com/block/ftl/internal/projectconfig"
 	"github.com/block/ftl/internal/schema/schemaeventsource"
 )
@@ -25,6 +26,7 @@ func (b *buildCmd) Run(
 	schemaSourceFactory func() schemaeventsource.EventSource,
 	projConfig projectconfig.Config,
 ) error {
+	logger := log.FromContext(ctx)
 	if len(b.Dirs) == 0 {
 		b.Dirs = projConfig.AbsModuleDirs()
 	}
@@ -48,6 +50,10 @@ func (b *buildCmd) Run(
 	if err != nil {
 		return err
 	}
+	if len(engine.Modules()) == 0 {
+		logger.Warnf("No modules were found to build")
+		return nil
+	}
 	if err := engine.Build(ctx); err != nil {
 		return fmt.Errorf("build failed: %w", err)
 	}
diff --git a/cmd/ftl/cmd_deploy.go b/cmd/ftl/cmd_deploy.go
index b41dd2c4b8..b5fd8c2e52 100644
--- a/cmd/ftl/cmd_deploy.go
+++ b/cmd/ftl/cmd_deploy.go
@@ -7,6 +7,7 @@ import (
 
 	provisionerconnect "github.com/block/ftl/backend/protos/xyz/block/ftl/provisioner/v1beta1/provisionerpbconnect"
 	"github.com/block/ftl/internal/buildengine"
+	"github.com/block/ftl/internal/log"
 	"github.com/block/ftl/internal/projectconfig"
 	"github.com/block/ftl/internal/schema/schemaeventsource"
 )
@@ -24,6 +25,7 @@ func (d *deployCmd) Run(
 	provisionerClient provisionerconnect.ProvisionerServiceClient,
 	schemaSourceFactory func() schemaeventsource.EventSource,
 ) error {
+	logger := log.FromContext(ctx)
 	// Cancel build engine context to ensure all language plugins are killed.
 	if d.Timeout > 0 {
 		var cancel context.CancelFunc //nolint: forbidigo
@@ -42,7 +44,10 @@ func (d *deployCmd) Run(
 	if err != nil {
 		return err
 	}
-
+	if len(engine.Modules()) == 0 {
+		logger.Warnf("No modules were found to deploy")
+		return nil
+	}
 	err = engine.BuildAndDeploy(ctx, d.Replicas, !d.NoWait)
 	if err != nil {
 		return fmt.Errorf("failed to deploy: %w", err)