Fix rds.toJsonObject method only supporting string values (#122)

Currently, the `toJsonObject` method from `rds` only supports `{
stringValue: string }`, but other value types can appear in payloads,
such as `{ longValue: number }`, `{ doubleValue: number }`, etc. See
https://docs.aws.amazon.com/rdsdataservice/latest/APIReference/API_Field.html
for more information.

This PR changes `toJsonObject` so it extracts the values properly. It
also uses the row label if available, and the row name as a fallback.

Author: skyrpex

__tests__/__snapshots__/resolvers.test.js.snap

@@ -246,13 +246,41 @@ exports[`rds resolvers toJsonObject 1`] = `
 [
   [
     {
+      "IS ACTIVE": true,
       "ISBN-13": "978-1948132817",
       "author": "Mark Twain",
+      "blob_value": "aGVsbG8=",
+      "id": 12345,
+      "tags": [
+        "a",
+        "b",
+      ],
       "title": "Adventures of Huckleberry Finn",
     },
     {
+      "IS ACTIVE": false,
       "ISBN-13": "978-1948132275",
       "author": "Jack London",
+      "blob_value": "d29ybGQ=",
+      "id": 67890,
+      "optional_double": 12.34,
+      "tags": [
+        [
+          true,
+          false,
+        ],
+        [
+          1.234,
+        ],
+        [
+          1,
+          2,
+        ],
+        [
+          "a",
+          "b",
+        ],
+      ],
       "title": "The Call of the Wild",
     },
   ],

__tests__/resolvers.test.js

@@ -242,6 +242,9 @@ describe("rds resolvers", () => {
             "numberOfRecordsUpdated": 0,
             "records": [
               [
+                {
+                  "longValue": 12345
+                },
                 {
                   "stringValue": "Mark Twain"
                 },
@@ -250,9 +253,18 @@ describe("rds resolvers", () => {
                 },
                 {
                   "stringValue": "978-1948132817"
-                }
+                },
+                {
+                  "isNull": true
+                },
+                { "arrayValue": { "stringValues": ["a", "b"] } },
+                { "booleanValue": true },
+                { "blobValue": Buffer.from("hello").toString("base64") }
               ],
               [
+                {
+                  "longValue": 67890
+                },
                 {
                   "stringValue": "Jack London"
                 },
@@ -261,10 +273,39 @@ describe("rds resolvers", () => {
                 },
                 {
                   "stringValue": "978-1948132275"
-                }
+                },
+                {
+                  "doubleValue": 12.34,
+                },
+                { "arrayValue": {
+                    "arrayValues": [
+                      { "booleanValues": [true, false] },
+                      { "doubleValues": [1.234] },
+                      { "longValues": [1, 2] },
+                      { "stringValues": ["a", "b"] },
+                    ],
+                  },
+                },
+                { "booleanValue": false },
+                { "blobValue": Buffer.from("world").toString("base64") },
               ]
             ],
             "columnMetadata": [
+              {
+                "type": 4,
+                "typeName": "serial",
+                "label": "id",
+                "schemaName": "",
+                "tableName": "Books",
+                "isAutoIncrement": true,
+                "isSigned": true,
+                "isCurrency": false,
+                "isCaseSensitive": false,
+                "nullable": 0,
+                "precision": 10,
+                "scale": 0,
+                "arrayBaseColumnType": 0
+              },
               {
                 "isSigned": false,
                 "isCurrency": false,
@@ -312,7 +353,20 @@ describe("rds resolvers", () => {
                 "nullable": 0,
                 "arrayBaseColumnType": 0,
                 "name": "ISBN-13"
-              }
+              },
+              {
+                "name": "optional_double",
+              },
+              {
+                "name": "tags",
+              },
+              {
+                "name": "is_active",
+                "label": "IS ACTIVE",
+              },
+              {
+                "name": "blob_value",
+              },
             ]
           }
         ]

rds/index.js

@@ -1,3 +1,31 @@
+/**
+ * Extract the value from the field given a row from sqlStatementResults.
+ * 
+ * See https://docs.aws.amazon.com/rdsdataservice/latest/APIReference/API_Field.html.
+ */
+function extractFieldValue(field) {
+  // Handle isNull.
+  if (field.isNull === true) {
+    return null;
+  }
+
+  // Handle arrayValue.
+  if ('arrayValue' in field) {
+    const { arrayValue } = field;
+
+    // Handle arrayValues.
+    if (arrayValue.arrayValues) {
+      return arrayValue.arrayValues.map(field => extractFieldValue(field));
+    }
+    
+    // Handle stringValues, doubleValues, longValues and booleanValues.
+    return Object.values(arrayValue)[0] ?? [];
+  }
+
+  // Handle stringValue, doubleValue, longValue, booleanValue and blobValue.
+  return Object.values(field)[0];
+}
+
 export function toJsonObject(inputStr) {
   // on AWS inputStr is always a string, but on LocalStack the input may be an object.
   let input;
@@ -20,12 +48,15 @@ export function toJsonObject(inputStr) {
         }
 
         for (const colNo in record) {
-
-          // TODO: what if the column is not a string?
-          const { stringValue } = record[colNo];
-          const { label } = columnMetadata[colNo];
-
-          row[label] = stringValue;
+          // Use label if available, otherwise use name.
+          const metadata = columnMetadata[colNo];
+          const colName = metadata.label ?? metadata.name;
+
+          // Extract the value from the field.
+          const value = extractFieldValue(record[colNo]);
+          if (value !== null) {
+            row[colName] = value;
+          }
         }
 
         statement.push(row);