Basic template parsing, tests, build command progress

packer/build_command.go

 package packer
 
+import (
+	"io/ioutil"
+)
+
 type buildCommand byte
 
 func (buildCommand) Run(env *Environment, args []string) int {
+	if len(args) != 1 {
+		// TODO: Error message
+		return 1
+	}
+
+	// Read the file into a byte array so that we can parse the template
+	tplData, err := ioutil.ReadFile(args[0])
+	if err != nil {
+		// TODO: Error message
+		return 1
+	}
+
+	// Parse the template into a machine-usable format
+	_, err = ParseTemplate(tplData)
+	if err != nil {
+		// TODO: error message
+		return 1
+	}
+
 	return 0
 }
 

packer/build_command_test.go

+package packer
+
+import (
+	"cgl.tideland.biz/asserts"
+	"testing"
+)
+
+func TestBuildCommand_Run_NoArgs(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+	command := new(buildCommand)
+	result := command.Run(testEnvironment(), make([]string, 0))
+	assert.Equal(result, 1, "no args should error")
+}
+
+func TestBuildCommand_Run_MoreThanOneArg(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+	command := new(buildCommand)
+
+	args := []string{"one", "two"}
+	result := command.Run(testEnvironment(), args)
+	assert.Equal(result, 1, "More than one arg should fail")
+}
+
+func TestBuildCommand_Run_MissingFile(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+	command := new(buildCommand)
+
+	args := []string{"i-better-not-exist"}
+	result := command.Run(testEnvironment(), args)
+	assert.Equal(result, 1, "a non-existent file should error")
+}

packer/template.go

@@ -27,12 +27,16 @@ type rawBuilderConfig struct {
 	rawConfig   interface{}
 }
 
-func parseTemplate(data []byte) error {
+func ParseTemplate(data []byte) (t *Template, err error) {
 	var rawTpl rawTemplate
-	err := json.Unmarshal(data, &rawTpl)
+	err = json.Unmarshal(data, &rawTpl)
 	if err != nil {
-		return err
+		return
 	}
 
-	return nil
+	t = &Template{
+		Name: rawTpl.Name,
+	}
+
+	return
 }

packer/template_test.go

+package packer
+
+import (
+	"cgl.tideland.biz/asserts"
+	"testing"
+)
+
+func TestParseTemplate_Basic(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	data := `
+	{
+		"name": "my-image",
+		"builders": []
+	}
+	`
+
+	result, err := ParseTemplate([]byte(data))
+	assert.Nil(err, "should not error")
+	assert.NotNil(result, "template should not be nil")
+	assert.Equal(result.Name, "my-image", "name should be correct")
+	assert.Length(result.Builders, 0, "no builders")
+}
+
+func TestParseTemplate_Invalid(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	// Note there is an extra comma below for a purposeful
+	// syntax error in the JSON.
+	data := `
+	{
+		"name": "my-image",,
+		"builders": []
+	}
+	`
+
+	result, err := ParseTemplate([]byte(data))
+	assert.NotNil(err, "should have an error")
+	assert.Nil(result, "should have no result")
+}