feat(firestore, android): variable implementation

Author: russellwheatley

packages/firestore/android/src/reactnative/java/io/invertase/firebase/firestore/ReactNativeFirebaseFirestorePipelineNodeBuilder.java

@@ -994,6 +994,22 @@ private void processObjectLoweringStack(ArrayDeque<ObjectLoweringFrame> stack)
             break;
           }
 
+          Object exprType = map.get("exprType");
+          if (exprType instanceof String
+              && "variable".equals(((String) exprType).toLowerCase(Locale.ROOT))) {
+            Object nameValue = map.get("name");
+            if (!(nameValue instanceof String) || ((String) nameValue).isEmpty()) {
+              throw new ReactNativeFirebaseFirestorePipelineExecutor.PipelineValidationException(
+                  "pipelineExecute() expected "
+                      + currentFieldName
+                      + ".name to be a non-empty string.");
+            }
+            enterFrame.box.value =
+                applyPendingUnaryExpressionFunctions(
+                    Expression.variable((String) nameValue), pendingUnaryFunctions);
+            break;
+          }
+
           Object name = map.get("name");
           if (name instanceof String) {
             String functionName = (String) name;
@@ -1022,7 +1038,7 @@ private void processObjectLoweringStack(ArrayDeque<ObjectLoweringFrame> stack)
             break;
           }
 
-          Object exprType = map.get("exprType");
+          exprType = map.get("exprType");
           if (exprType instanceof String) {
             String normalizedType = ((String) exprType).toLowerCase(Locale.ROOT);
             if ("field".equals(normalizedType)) {
@@ -3287,6 +3303,19 @@ private Object serializeExpressionNode(
           continue;
         }
 
+        if (expression
+            instanceof ReactNativeFirebaseFirestorePipelineParser.ParsedVariableExpressionNode) {
+          Map<String, Object> output = new LinkedHashMap<>();
+          output.put("__kind", "expression");
+          output.put("exprType", "Variable");
+          output.put(
+              "name",
+              ((ReactNativeFirebaseFirestorePipelineParser.ParsedVariableExpressionNode) expression)
+                  .name);
+          enterFrame.box.value = output;
+          continue;
+        }
+
         ReactNativeFirebaseFirestorePipelineParser.ParsedFunctionExpressionNode function =
             (ReactNativeFirebaseFirestorePipelineParser.ParsedFunctionExpressionNode) expression;
         List<SerializedValueBox> argBoxes = new ArrayList<>(function.args.size());
@@ -3532,6 +3561,19 @@ private Object serializeValueNode(
           continue;
         }
 
+        if (expression
+            instanceof ReactNativeFirebaseFirestorePipelineParser.ParsedVariableExpressionNode) {
+          Map<String, Object> output = new LinkedHashMap<>();
+          output.put("__kind", "expression");
+          output.put("exprType", "Variable");
+          output.put(
+              "name",
+              ((ReactNativeFirebaseFirestorePipelineParser.ParsedVariableExpressionNode) expression)
+                  .name);
+          enterFrame.box.value = output;
+          continue;
+        }
+
         ReactNativeFirebaseFirestorePipelineParser.ParsedFunctionExpressionNode function =
             (ReactNativeFirebaseFirestorePipelineParser.ParsedFunctionExpressionNode) expression;
         List<SerializedValueBox> argBoxes = new ArrayList<>(function.args.size());

packages/firestore/android/src/reactnative/java/io/invertase/firebase/firestore/ReactNativeFirebaseFirestorePipelineParser.java

@@ -943,6 +943,15 @@ private static void parseExpressionValueTree(ExpressionValueParseFrame initialFr
               stack.push(new ValueEnterFrame(map.get("value"), valueBox, fieldName + ".value"));
               continue;
             }
+            if ("variable".equals(normalizedType)) {
+              Object nameValue = map.get("name");
+              if (!(nameValue instanceof String) || ((String) nameValue).isEmpty()) {
+                throw new ReactNativeFirebaseFirestorePipelineExecutor.PipelineValidationException(
+                    "pipelineExecute() expected " + fieldName + ".name to be a non-empty string.");
+              }
+              enterFrame.box.value = new ParsedVariableExpressionNode((String) nameValue);
+              continue;
+            }
           }
 
           if (map.containsKey("name")) {
@@ -1636,6 +1645,14 @@ static final class ParsedConstantExpressionNode extends ParsedExpressionNode {
     }
   }
 
+  static final class ParsedVariableExpressionNode extends ParsedExpressionNode {
+    final String name;
+
+    ParsedVariableExpressionNode(String name) {
+      this.name = name;
+    }
+  }
+
   static final class ParsedFunctionExpressionNode extends ParsedExpressionNode {
     final String name;
     final List<ParsedValueNode> args;