Dryrun: Improve assembler error reporting (#5889)

daemon/algod/api/server/v2/dryrun.go

@@ -89,7 +89,12 @@ func (dr *DryrunRequest) ExpandSources() error {
 	for i, s := range dr.Sources {
 		ops, err := logic.AssembleString(s.Source)
 		if err != nil {
-			return fmt.Errorf("dryrun Source[%d]: %v", i, err)
+			if len(ops.Errors) <= 1 {
+				return fmt.Errorf("dryrun Source[%d]: %w", i, err)
+			}
+			var sb strings.Builder
+			ops.ReportMultipleErrors("", &sb)
+			return fmt.Errorf("dryrun Source[%d]: %d errors\n%s", i, len(ops.Errors), sb.String())
 		}
 		switch s.FieldName {
 		case "lsig":

daemon/algod/api/server/v2/dryrun_test.go

@@ -132,6 +132,48 @@ func logResponse(t *testing.T, response *model.DryrunResponse) {
 var dryrunProtoVersion protocol.ConsensusVersion = protocol.ConsensusFuture
 var dryrunMakeLedgerProto protocol.ConsensusVersion = "dryrunMakeLedgerProto"
 
+func TestDryrunSources(t *testing.T) {
+	partitiontest.PartitionTest(t)
+	t.Parallel()
+
+	goodSource := model.DryrunSource{
+		AppIndex:  1007,
+		FieldName: "approv",
+		Source: `#pragma version 10
+int 1`,
+	}
+	badSource := model.DryrunSource{
+		AppIndex:  1007,
+		FieldName: "approv",
+		Source: `#pragma version 10
+int 1
+pop
+fake_opcode
+int not_an_int`,
+	}
+
+	dr := DryrunRequest{
+		Sources: []model.DryrunSource{
+			goodSource,
+		},
+		Apps: []model.Application{
+			{
+				Id: 1007,
+			},
+		},
+	}
+	var response model.DryrunResponse
+
+	doDryrunRequest(&dr, &response)
+	require.Empty(t, response.Error)
+
+	dr.Sources[0] = badSource
+	doDryrunRequest(&dr, &response)
+	require.Contains(t, response.Error, "dryrun Source[0]: 2 errors")
+	require.Contains(t, response.Error, "4: unknown opcode: fake_opcode")
+	require.Contains(t, response.Error, "5:4: unable to parse \"not_an_int\" as integer")
+}
+
 func TestDryrunLogicSig(t *testing.T) {
 	partitiontest.PartitionTest(t)
 	// {"txns":[{"lsig":{"l":"AiABASI="},"txn":{}}]}