feat(placeholder): Pass stderr to ReplacePlaceholders

Pass stderr to ReplacePlaceholders and add test cases for the function.

internal/placeholder/placeholder.go

@@ -3,7 +3,7 @@ package placeholder
 import (
 	"bufio"
 	"fmt"
-	"os"
+	"io"
 	"path/filepath"
 	"strings"
 
@@ -12,7 +12,7 @@ import (
 )
 
 // ReplacePlaceholders replaces placeholders in Script with Placeholders
-func ReplacePlaceholders(fs afero.Fs, baseDir string, params *models.Params) (string, error) {
+func ReplacePlaceholders(stderr io.Writer, fs afero.Fs, baseDir string, params *models.Params) (string, error) {
 	var err error
 
 	script := params.Script
@@ -37,13 +37,13 @@ func ReplacePlaceholders(fs afero.Fs, baseDir string, params *models.Params) (st
 			// static Value
 			value = placeholder.Value
 		} else {
-			fmt.Fprintf(os.Stderr, "WARNING: Neither File nor Value are set for placeholder '%s'", placeholder.Name)
+			fmt.Fprintf(stderr, "WARNING: Neither File nor Value are set for placeholder '%s'", placeholder.Name)
 		}
 
 		if strings.Contains(script, placeholder.Name) {
 			script = strings.Replace(script, placeholder.Name, value, -1)
 		} else {
-			fmt.Fprintf(os.Stderr, "WARNINIG: Placeholder '%s' is not found in script, maybe a typo?", placeholder.Name)
+			fmt.Fprintf(stderr, "WARNINIG: Placeholder '%s' is not found in script, maybe a typo?", placeholder.Name)
 		}
 	}
 

internal/placeholder/placeholder_test.go

@@ -0,0 +1,114 @@
+package placeholder
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/henry40408/concourse-ssh-resource/internal/models"
+)
+
+const (
+	baseDir = "/tmp"
+)
+
+func TestReplacePlaceholdersWithValue(t *testing.T) {
+	stderr := bytes.NewBuffer([]byte{})
+
+	fs := afero.NewMemMapFs()
+	params := &models.Params{
+		Script: `echo "<placeholder>"`,
+		Placeholders: []models.Placeholder{
+			models.Placeholder{Name: "<placeholder>", Value: "foobar"},
+		},
+	}
+
+	script, err := ReplacePlaceholders(stderr, fs, baseDir, params)
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	assert.Equal(t, `echo "foobar"`, script)
+}
+
+func TestReplacePlaceholdersWithFile(t *testing.T) {
+	stderr := bytes.NewBuffer([]byte{})
+
+	fs := afero.NewMemMapFs()
+	fs.MkdirAll(baseDir, 0755)
+	afero.WriteFile(fs, "/tmp/somefile", []byte("foobar"), 0644)
+
+	params := &models.Params{
+		Script: `echo "<placeholder>"`,
+		Placeholders: []models.Placeholder{
+			models.Placeholder{Name: "<placeholder>", File: "somefile"},
+		},
+	}
+
+	script, err := ReplacePlaceholders(stderr, fs, baseDir, params)
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	assert.Equal(t, `echo "foobar"`, script)
+}
+
+func TestReplacePlaceholdersWithEmptyFile(t *testing.T) {
+	stderr := bytes.NewBuffer([]byte{})
+
+	fs := afero.NewMemMapFs()
+	fs.MkdirAll(baseDir, 0755)
+	afero.WriteFile(fs, "/tmp/somefile", []byte(""), 0644)
+
+	params := &models.Params{
+		Script: `echo "<placeholder>"`,
+		Placeholders: []models.Placeholder{
+			models.Placeholder{Name: "<placeholder>", File: "somefile"},
+		},
+	}
+
+	_, err := ReplacePlaceholders(stderr, fs, baseDir, params)
+	if assert.Error(t, err) {
+		assert.Contains(t, err.Error(), "File for placeholder '<placeholder>' seems to be empty")
+	}
+}
+
+func TestReplacePlaceholdersWithNonusedPlaceholder(t *testing.T) {
+	stderr := bytes.NewBuffer([]byte{})
+	fs := afero.NewMemMapFs()
+	params := &models.Params{
+		Script: `echo "<placeholder>"`,
+		Placeholders: []models.Placeholder{
+			models.Placeholder{Name: "<place>", Value: "foobar"},
+		},
+	}
+
+	_, err := ReplacePlaceholders(stderr, fs, baseDir, params)
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	assert.Contains(t, stderr.String(), "Placeholder '<place>' is not found in script")
+}
+
+func TestReplacePlaceholdersWithPlaceholderWhichHasNoValueNorFile(t *testing.T) {
+	fs := afero.NewMemMapFs()
+
+	params := &models.Params{
+		Script: `echo "<placeholder>"`,
+		Placeholders: []models.Placeholder{
+			models.Placeholder{Name: "<placeholder>"},
+		},
+	}
+
+	stderr := bytes.NewBuffer([]byte{})
+
+	_, err := ReplacePlaceholders(stderr, fs, baseDir, params)
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	assert.Contains(t, stderr.String(), "Neither File nor Value are set for placeholder '<placeholder>'")
+}

internal/ssh/ssh.go

@@ -39,7 +39,7 @@ func PerformSSHCommand(fs afero.Fs, source *models.Source, params *models.Params
 		interpreter = "/bin/sh"
 	}
 
-	script, err := placeholder.ReplacePlaceholders(fs, baseDir, params)
+	script, err := placeholder.ReplacePlaceholders(stderr, fs, baseDir, params)
 	if err != nil {
 		return hierr.Errorf(err, "unable to replace placeholders")
 	}