modified parameter injection strategy. see #538

shared/build/script/inject.go

@@ -0,0 +1,16 @@
+package script
+
+import (
+	"strings"
+)
+
+func Inject(script string, params map[string]string) string {
+	if params == nil {
+		return script
+	}
+	injected := script
+	for k, v := range params {
+		injected = strings.Replace(injected, "$$"+k, v, -1)
+	}
+	return injected
+}

shared/build/script/inject_test.go

@@ -0,0 +1,32 @@
+package script
+
+import (
+	"github.com/franela/goblin"
+	"testing"
+)
+
+func Test_Inject(t *testing.T) {
+
+	g := goblin.Goblin(t)
+	g.Describe("Inject params", func() {
+
+		g.It("Should replace vars with $$", func() {
+			s := "echo $$FOO $BAR"
+			m := map[string]string{}
+			m["FOO"] = "BAZ"
+			g.Assert("echo BAZ $BAR").Equal(Inject(s, m))
+		})
+
+		g.It("Should not replace vars with single $", func() {
+			s := "echo $FOO $BAR"
+			m := map[string]string{}
+			m["FOO"] = "BAZ"
+			g.Assert(s).Equal(Inject(s, m))
+		})
+
+		g.It("Should not replace vars in nil map", func() {
+			s := "echo $$FOO $BAR"
+			g.Assert(s).Equal(Inject(s, nil))
+		})
+	})
+}

shared/build/script/script.go

@@ -1,8 +1,6 @@
 package script
 
 import (
-	"bytes"
-	"fmt"
 	"io/ioutil"
 	"strings"
 
@@ -16,11 +14,11 @@ import (
 	"github.com/drone/drone/shared/build/repo"
 )
 
-func ParseBuild(data string, params map[string]string) (*Build, error) {
+func ParseBuild(data string) (*Build, error) {
 	build := Build{}
 
 	// parse the build configuration file
-	err := yaml.Unmarshal(injectParams([]byte(data), params), &build)
+	err := yaml.Unmarshal([]byte(data), &build)
 	return &build, err
 }
 
@@ -30,15 +28,7 @@ func ParseBuildFile(filename string) (*Build, error) {
 		return nil, err
 	}
 
-	return ParseBuild(string(data), nil)
-}
-
-// injectParams injects params into data.
-func injectParams(data []byte, params map[string]string) []byte {
-	for k, v := range params {
-		data = bytes.Replace(data, []byte(fmt.Sprintf("{{%s}}", k)), []byte(v), -1)
-	}
-	return data
+	return ParseBuild(string(data))
 }
 
 // Build stores the configuration details for