From c7695ea2798bd77fab03089cabee77efbc00a4b1 Mon Sep 17 00:00:00 2001
From: bwireman <bwireman1@gmail.com>
Date: Sun, 6 Feb 2022 15:07:29 -0600
Subject: [PATCH] cleanup flags and module

---
 README.md           |  2 +-
 pkg/gleam/format.go |  8 +++-----
 pkg/gleam/gpb.go    | 10 +++++-----
 pkg/gleam/module.go | 12 +++++++++---
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 5d918bd..a5991cc 100644
--- a/README.md
+++ b/README.md
@@ -159,7 +159,7 @@ Example Script
 
 ```bash
 # make sure protoc-gen-gleam is in you're path or add it manually using --plugin
-protoc --plugin=protoc-gen-gleam -I . --gleam_out="src" protos/*.proto
+protoc --plugin=protoc-gen-gleam -I . --gleam_out="output_path=./src:./src" protos/*.proto
 ```
 
 ### `gleam_pb` Flags
diff --git a/pkg/gleam/format.go b/pkg/gleam/format.go
index 38efdc1..1b2f546 100644
--- a/pkg/gleam/format.go
+++ b/pkg/gleam/format.go
@@ -22,14 +22,12 @@ func (gf GleamFormatter) Match(a pgs.Artifact) bool {
 	}
 }
 
-func (gf GleamFormatter) Process(in []byte) (stdout []byte, err error) {
+func (gf GleamFormatter) Process(in []byte) ([]byte, error) {
 	cmd := exec.Command("gleam", "format", "--stdin")
 	cmd.Stdin = bytes.NewReader(in)
-
-	stdout, err = cmd.Output()
+	stdout, err := cmd.Output()
 	if err != nil {
-		fmt.Println(err.Error())
-		return
+		return nil, fmt.Errorf("Error formating generated gleam code: %s", string(stdout))
 	}
 
 	return stdout, nil
diff --git a/pkg/gleam/gpb.go b/pkg/gleam/gpb.go
index 21d5e1b..9aa619f 100644
--- a/pkg/gleam/gpb.go
+++ b/pkg/gleam/gpb.go
@@ -11,11 +11,6 @@ type gpbWrapper struct {
 	pathToBinary string
 }
 
-func exists(path string) bool {
-	_, err := os.Open(path)
-	return !errors.Is(err, os.ErrNotExist)
-}
-
 func newGPBWrapper(pathToBinary string) (*gpbWrapper, error) {
 	if !exists(pathToBinary) {
 		return nil, fmt.Errorf("protoc-erl could not be found at %s", pathToBinary)
@@ -39,3 +34,8 @@ func (g *gpbWrapper) generate(targets []string, outputPath string) (err error) {
 
 	return nil
 }
+
+func exists(path string) bool {
+	_, err := os.Open(path)
+	return !errors.Is(err, os.ErrNotExist)
+}
diff --git a/pkg/gleam/module.go b/pkg/gleam/module.go
index e62bf89..530e16a 100644
--- a/pkg/gleam/module.go
+++ b/pkg/gleam/module.go
@@ -10,15 +10,21 @@ import (
 
 type GleamModule struct {
 	*pgs.ModuleBase
-	tpl *template.Template
+	tpl           *template.Template
+	protocErlPath string
+	output        string
 }
 
 func Gleam() *GleamModule { return &GleamModule{ModuleBase: &pgs.ModuleBase{}} }
 
 func (g *GleamModule) InitContext(c pgs.BuildContext) {
 	g.ModuleBase.InitContext(c)
-
+	g.protocErlPath = g.Parameters().StrDefault("protoc_erl_path", "./deps/gpb/bin/protoc-erl")
 	g.tpl = template.Must(template.New("gleam-package-template").Parse(fields.GleamTemplate))
+
+	if g.output = g.Parameters().Str("output_path"); g.output == "" {
+		g.Fail("please specify the `output_path` flag")
+	}
 }
 
 func (g *GleamModule) Name() string { return "gleam" }
@@ -31,7 +37,7 @@ func (g *GleamModule) Execute(targets map[string]pgs.File, pkgs map[string]pgs.P
 		}
 	}
 
-	wrapper, err := newGPBWrapper(g.Parameters().StrDefault("protoc_erl_path", "./deps/gpb/bin/protoc-erl"))
+	wrapper, err := newGPBWrapper(g.protocErlPath)
 	if err != nil {
 		g.Fail(err.Error())
 	}