Fix changelog generation when querying submodules

src/changelog/main.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"strings"
 )
 
 var (
@@ -51,17 +50,19 @@ func main() {
 
 	skipSubmodule := os.Getenv("SKIP_SUBMODULE")
 	if skipSubmodule != "true" {
+		fmt.Printf("Also querying submodule for changes...\n")
 		//git ls-tree HEAD src/app-autoscaler | awk '{print $3}'
-		toSha, err := getShaOfSubmoduleAtCommit("HEAD")
+		toSha, err := util.GetShaOfSubmoduleAtCommit("HEAD")
 		if err != nil {
 			panic(err)
 		}
 
-		fromSha, err := getShaOfSubmoduleAtCommit(commit)
+		fromSha, err := util.GetShaOfSubmoduleAtCommit(commit)
 		if err != nil {
 			panic(err)
 		}
 
+		fmt.Printf("Checking from %s to %s\n", fromSha, toSha)
 		if fromSha != toSha {
 			// get PRs from app-autoscaler too
 			otherPRs, err := client.FetchPullRequestsAfterCommit(owner, "app-autoscaler", branch, fromSha, toSha)
@@ -98,16 +99,3 @@ func main() {
 
 	fmt.Printf("Total PRs %d\n", len(prs))
 }
-
-func getShaOfSubmoduleAtCommit(commit string) (string, error) {
-	cmd := util.Command{Name: "git", Args: []string{"ls-tree", commit, "../app-autoscaler"}}
-	runner := util.DefaultCommandRunner{}
-
-	output, err := runner.RunWithoutRetry(&cmd)
-	if err != nil {
-		return "", err
-	}
-
-	parts := strings.Split(output, " ")
-	return parts[2], nil
-}

src/changelog/util/git.go

@@ -0,0 +1,19 @@
+package util
+
+import "strings"
+
+var Runner CommandRunner
+
+func GetShaOfSubmoduleAtCommit(commit string) (string, error) {
+	cmd := Command{Name: "git", Args: []string{"ls-tree", commit, "../app-autoscaler"}}
+	if Runner == nil {
+		Runner = DefaultCommandRunner{}
+	}
+	output, err := Runner.RunWithoutRetry(&cmd)
+	if err != nil {
+		return "", err
+	}
+
+	parts := strings.Split(output, " ")
+	return strings.Split(parts[2], "\t")[0], nil
+}

src/changelog/util/git_test.go

@@ -0,0 +1,23 @@
+package util_test
+
+import (
+	"changelog/util"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetShaOfSubmoduleAtCommit(t *testing.T) {
+	util.Runner = &FakeCommandRunner{}
+	sha, err := util.GetShaOfSubmoduleAtCommit("HEAD")
+	assert.NoError(t, err)
+	assert.Equal(t, sha, "e57e6dccf303e621ec4239b5d97aeba168a6de50")
+}
+
+type FakeCommandRunner struct {
+}
+
+// RunWithoutRetry Execute the command without retrying on failure and block waiting for return values.
+func (d FakeCommandRunner) RunWithoutRetry(c *util.Command) (string, error) {
+	return "160000 commit e57e6dccf303e621ec4239b5d97aeba168a6de50\t../app-autoscaler", nil
+}