Fix file path when fetching notes (#184)

* Fix file path when fetching notes

This commit fixes the path we request from github to retrieve a commit's
notes.

Signed-off-by: Adolfo Garcia Veytia (puerco) <puerco@carabiner.dev>

* Add local GetNotesForCommit unit test

This commit adds a unit test for the GetNotesForCommit func that
connects to the github api. It will be skipped if no token is set
in the environment.

Signed-off-by: Adolfo Garcia Veytia (puerco) <puerco@carabiner.dev>

* Fix bug passing token from env

Signed-off-by: Adolfo Garcia Veytia (puerco) <puerco@carabiner.dev>

---------

Signed-off-by: Adolfo Garcia Veytia (puerco) <puerco@carabiner.dev>

Author: puerco

sourcetool/pkg/gh_control/connection.go

@@ -37,7 +37,7 @@ func NewGhConnectionWithClient(owner, repo, ref string, client *github.Client) *
 		owner:   owner,
 		repo:    repo,
 		ref:     ref,
-		Options: defaultOptions,
+		Options: opts,
 	}
 }
 

sourcetool/pkg/gh_control/notes.go

@@ -8,12 +8,15 @@ import (
 	"github.com/google/go-github/v69/github"
 )
 
+// GetNotesForCommit returns the unparsed notes blob for a commit as stored in git via the GitHub API.
 func (ghc *GitHubConnection) GetNotesForCommit(ctx context.Context, commit string) (string, error) {
 	// We can find the notes for a given commit fairly easily.
-	// They'll be in the path <commit> within ref `refs/notes/commits`
-
+	// They'll be in the path <co/mmit> within ref `refs/notes/commits`
+	// where the first two characters of the commit sha are separated from the
+	// rest with a slash, eg e5/73149ab3e574abc2e5a151a04acfaf2a59b453.
+	path := commit[0:2] + "/" + commit[2:]
 	contents, _, resp, err := ghc.Client().Repositories.GetContents(
-		ctx, ghc.Owner(), ghc.Repo(), commit, &github.RepositoryContentGetOptions{Ref: "refs/notes/commits"})
+		ctx, ghc.Owner(), ghc.Repo(), path, &github.RepositoryContentGetOptions{Ref: "refs/notes/commits"})
 
 	if resp.StatusCode == http.StatusNotFound {
 		// Don't freak out if it's not there.

sourcetool/pkg/gh_control/notes_test.go

@@ -0,0 +1,44 @@
+package gh_control
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetNotesForCommit(t *testing.T) {
+	if tk := os.Getenv(tokenEnvVar); tk == "" {
+		t.Log("Skipping API test as no token is set")
+		t.Skip()
+	}
+	t.Parallel()
+	for _, tc := range []struct {
+		name        string
+		owner       string
+		repo        string
+		commit      string
+		mustBeEmpty bool
+		mustErr     bool
+	}{
+		{name: "success", owner: "slsa-framework", repo: "slsa-source-poc", commit: "e573149ab3e574abc2e5a151a04acfaf2a59b453", mustBeEmpty: false, mustErr: false},
+		{name: "non-existent", owner: "kjsdhi373iuh", repo: "lksjdhfk3773", commit: "invalid", mustBeEmpty: true, mustErr: false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			ghc := NewGhConnection(tc.owner, tc.repo, "main")
+			notes, err := ghc.GetNotesForCommit(context.Background(), tc.commit)
+			if tc.mustErr {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err, tc.commit)
+			if tc.mustBeEmpty {
+				require.Empty(t, notes, "Commit: %s", tc.commit)
+			} else {
+				require.NotEmpty(t, notes, "Commit: %s", tc.commit)
+			}
+		})
+	}
+}