From 4881ad9211360da8b2256fdb05a75614aa6b7291 Mon Sep 17 00:00:00 2001
From: Andrew Chiw <randomshinichi4869@gmail.com>
Date: Fri, 5 Apr 2019 15:17:37 +0200
Subject: [PATCH] chore: separate salt generation from calculating the
 commitmentId, so we can unittest commitmentId generation against GET
 /v2/debug/names/commitment-id

---
 aeternity/hashing.go      | 14 +++++++---
 aeternity/hashing_test.go | 55 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/aeternity/hashing.go b/aeternity/hashing.go
index 9ef6657a..b8f7a68d 100644
--- a/aeternity/hashing.go
+++ b/aeternity/hashing.go
@@ -110,16 +110,22 @@ func uuidV4() (u string) {
 	return fmt.Sprint(uuid.NewV4())
 }
 
-// naming
-func computeCommitmentID(name string) (ch string, salt []byte, err error) {
+// since the salt is a uint256, which Erlang handles well, but Go has nothing similar to it,
+// it is imperative that the salt be kept as a bytearray unless you really have to convert it
+// into an integer. Which you usually don't, because it's a salt.
+func generateCommitmentID(name string) (ch string, salt []byte, err error) {
 	salt, err = randomBytes(32)
 	if err != nil {
 		return
 	}
-	// TODO: this is done using the api (concatenating )
+
+	ch, err = computeCommitmentID(name, salt)
+	return ch, salt, err
+}
+
+func computeCommitmentID(name string, salt []byte) (ch string, err error) {
 	nh := append(Namehash(name), salt...)
 	nh, _ = hash(nh)
-	// nh := namehash(name)
 	ch = Encode(PrefixCommitment, nh)
 	return
 }
diff --git a/aeternity/hashing_test.go b/aeternity/hashing_test.go
index 6ff9eff0..d1f79d94 100644
--- a/aeternity/hashing_test.go
+++ b/aeternity/hashing_test.go
@@ -186,3 +186,58 @@ func TestGenerate(t *testing.T) {
 		})
 	}
 }
+
+func Test_computeCommitmentID(t *testing.T) {
+	type args struct {
+		name string
+		salt []byte
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantCh  string
+		wantErr bool
+	}{
+		{
+			name: "fdsa.test, 0",
+			args: args{
+				name: "fdsa.test",
+				salt: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+			},
+			wantCh:  "cm_2jJov6dn121oKkHo6TuWaAAL4ZEMonnCjpo8jatkCixrLG8Uc4",
+			wantErr: false,
+		},
+		{
+			name: "fdsa.test, 255",
+			args: args{
+				name: "fdsa.test",
+				salt: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255},
+			},
+			wantCh:  "cm_sa8UUjorPzCTLfYp6YftR4jwF4kPaZVsoP5bKVAqRw9zm43EE",
+			wantErr: false,
+		},
+		{
+			// erlang Eshell: rp(<<9795159241593061970:256>>).
+			name: "fdsa.test, 9795159241593061970 (do not use Golang to convert salt integers)",
+			args: args{
+				name: "fdsa.test",
+				salt: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 135, 239, 101, 110, 233, 138, 2, 82},
+			},
+			wantCh:  "cm_QhtcYow8krP3xQSTsAhFihfBstTjQMiApaPCgZuciDHZmMNtZ",
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// fmt.Println(saltBytes)
+			gotCh, err := computeCommitmentID(tt.args.name, tt.args.salt)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("computeCommitmentID() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if gotCh != tt.wantCh {
+				t.Errorf("computeCommitmentID() = %v, want %v", gotCh, tt.wantCh)
+			}
+		})
+	}
+}