client: add GetProofFromAddr function (#64)

Author: worm-emoji

clients/go/lanyard/client.go

@@ -208,14 +208,14 @@ type ProofResponse struct {
 	Proof        []hexutil.Bytes `json:"proof"`
 }
 
-// If the tree has been published to Lanyard, GetProof will
-// return the proof associated with an unHashedLeaf.
-// This endpoint will return ErrNotFound if the tree
-// associated with the root has not been published.
+// If the tree has been published to Lanyard,
+// GetProofFromLeaf will return the proof associated
+// with an unhashedLeaf. This endpoint will return
+// ErrNotFound if the tree associated with the root
+// has not been published.
 func (c *Client) GetProofFromLeaf(
 	ctx context.Context,
-	root hexutil.Bytes,
-	unhashedLeaf hexutil.Bytes,
+	root, unhashedLeaf hexutil.Bytes,
 ) (*ProofResponse, error) {
 	resp := &ProofResponse{}
 
@@ -234,6 +234,32 @@ func (c *Client) GetProofFromLeaf(
 	return resp, nil
 }
 
+// If the tree has been published to Lanyard,
+// GetProofFromAddr will return the proof associated
+// with an address. This endpoint will return
+// ErrNotFound if the tree associated with the root
+// has not been published.
+func (c *Client) GetProofFromAddr(
+	ctx context.Context,
+	root, addr hexutil.Bytes,
+) (*ProofResponse, error) {
+	resp := &ProofResponse{}
+
+	err := c.sendRequest(
+		ctx, http.MethodGet,
+		fmt.Sprintf("/proof?root=%s&address=%s",
+			root.String(), addr.String(),
+		),
+		nil, resp,
+	)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}
+
 type RootResponse struct {
 	Root hexutil.Bytes `json:"root"`
 }

clients/go/lanyard/client_integration_test.go

@@ -29,7 +29,10 @@ func init() {
 	}
 }
 
-const basicRoot = "0xa7a6b1cb6d12308ec4818baac3413fafa9e8b52cdcd79252fa9e29c9a2f8aff1"
+const (
+	basicRoot = "0xa7a6b1cb6d12308ec4818baac3413fafa9e8b52cdcd79252fa9e29c9a2f8aff1"
+	typedRoot = "0x6306f03ad6ae2ffeca080333a0a6828669192f5f8b61f70738bfe8ceb7e0a434"
+)
 
 func TestBasicMerkleTree(t *testing.T) {
 	tree, err := client.CreateTree(context.Background(), basicMerkle)
@@ -57,7 +60,6 @@ func TestCreateTypedTree(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	const typedRoot = "0x6306f03ad6ae2ffeca080333a0a6828669192f5f8b61f70738bfe8ceb7e0a434"
 	if tree.MerkleRoot.String() != typedRoot {
 		t.Fatalf("expected %s, got %s", typedRoot, tree.MerkleRoot.String())
 	}
@@ -77,6 +79,13 @@ func TestBasicMerkleProof404(t *testing.T) {
 	}
 }
 
+func TestGetProofFromAddr(t *testing.T) {
+	_, err := client.GetProofFromAddr(context.Background(), hexutil.MustDecode(typedRoot), hexutil.MustDecode("0x0000000000000000000000000000000000000001"))
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestGetRootFromProof(t *testing.T) {
 	p, err := client.GetProofFromLeaf(context.Background(), hexutil.MustDecode(basicRoot), basicMerkle[0])