Upgrade test to use JSON response:

It'd be nice if we had POST param unit tests but we don't :(

clients/stellarcore/client.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"path"
@@ -22,7 +21,7 @@ import (
 // Client represents a client that is capable of communicating with a
 // stellar-core server using HTTP
 type Client struct {
-	// HTTP is the client to use when communicating with stellar-core.  If nil,
+	// HTTP is the client to use when communicating with stellar-core. If nil,
 	// http.DefaultClient will be used.
 	HTTP HTTP
 
@@ -37,7 +36,7 @@ type Client struct {
 // in case an error was encountered during either the draining or closing of the
 // stream, that error would be returned.
 func drainReponse(hresp *http.Response, close bool, err *error) (outerror error) {
-	_, err2 := io.Copy(ioutil.Discard, hresp.Body)
+	_, err2 := io.Copy(io.Discard, hresp.Body)
 	if err2 != nil {
 		if err != nil && *err == nil {
 			*err = errors.Wrap(err2, "unable to read excess data from response")
@@ -320,7 +319,7 @@ func (c *Client) rawPost(
 
 // makeLedgerKeyRequest is a generic method to perform a request in the form
 // `key=...&key=...&ledgerSeq=...` which is useful because three Stellar Core
-// endpoints all use this request format. Be sure to pass `target by reference.
+// endpoints all use this request format. Be sure to pass `target` by reference.
 func (c *Client) makeLedgerKeyRequest(
 	ctx context.Context,
 	target interface{},
@@ -372,10 +371,15 @@ func (c *Client) getResponse(req *http.Request) (*http.Response, error) {
 func buildMultiKeyRequest(keys ...xdr.LedgerKey) (string, error) {
 	// The average ledger key length, according to a simple
 	//
-	// SELECT AVG(LENGTH(HEX(key))) / 2 FROM ledger_entries;
+	//     SELECT AVG(LENGTH(HEX(key))) / 2 FROM ledger_entries;
 	//
 	// on a pubnet RPC instance is ~57.6. We can use this to preallocate a
 	// string buffer for performance.
+	//
+	// We know that these endpoints will almost exclusively be used for
+	// ContractData and the like, so we could optimize the buffer further for
+	// that, but that data is harder to query since it'd involve parsing the XDR
+	// from the DB to check the key type.
 	q := strings.Builder{}
 	q.Grow(50 * len(keys))
 

clients/stellarcore/client_test.go

@@ -83,11 +83,24 @@ func TestGetLedgerEntries(t *testing.T) {
 	hmock := httptest.NewClient()
 	c := &Client{HTTP: hmock, URL: "http://localhost:11626"}
 
+	// build a fake response body
+	mockResp := proto.GetLedgerEntriesResponse{
+		Ledger: 1215, // checkpoint align on expected request
+		Entries: []proto.LedgerEntryResponse{
+			{
+				Entry: "pretend this is XDR lol",
+				State: proto.DeadState,
+			},
+			{
+				Entry: "pretend this is another XDR lol",
+				State: proto.ArchivedStateNoProof,
+			},
+		},
+	}
+
 	// happy path - fetch an entry
 	hmock.On("POST", "http://localhost:11626/getledgerentry").
-		ReturnString(http.StatusOK,
-			`{"ledger": 1234, "entries": [ {"e": "pretend it's xdr lol", "state": "dead" }]}`,
-		)
+		ReturnJSON(http.StatusOK, &mockResp)
 
 	var key xdr.LedgerKey
 	acc, err := xdr.AddressToAccountId(keypair.MustRandom().Address())
@@ -98,7 +111,8 @@ func TestGetLedgerEntries(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, resp)
 
-	require.EqualValues(t, 1234, resp.Ledger)
-	require.Len(t, resp.Entries, 1)
+	require.EqualValues(t, 1215, resp.Ledger)
+	require.Len(t, resp.Entries, 2)
 	require.Equal(t, resp.Entries[0].State, proto.DeadState)
+	require.Equal(t, resp.Entries[1].State, proto.ArchivedStateNoProof)
 }