fix: UUID type backward compatibility (#2509)

* fix: UUID type backward compatibility

* Flag to revert to the old behavior

Author: surbhigarg92

src/codec.ts

@@ -38,6 +38,8 @@ import * as uuid from 'uuid';
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type Value = any;
 
+let uuidUntypedFlagWarned = false;
+
 export interface Field {
   name: string;
   value: Value;
@@ -1160,8 +1162,17 @@ function getType(value: Value): Type {
     return {type: 'bool'};
   }
 
-  if (uuid.validate(value)) {
-    return {type: 'unspecified'};
+  if (process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'] === 'true') {
+    if (!uuidUntypedFlagWarned) {
+      process.emitWarning(
+        'SPANNER_ENABLE_UUID_AS_UNTYPED environment variable is deprecated and will be removed in a future release.',
+        'DeprecationWarning',
+      );
+      uuidUntypedFlagWarned = true;
+    }
+    if (uuid.validate(value)) {
+      return {type: 'unspecified'};
+    }
   }
 
   if (isString(value)) {

src/transaction.ts

@@ -1735,14 +1735,18 @@ export class Snapshot extends EventEmitter {
     if (!isEmpty(typeMap)) {
       Object.keys(typeMap).forEach(param => {
         const type = typeMap[param];
-        const typeObject = codec.createTypeObject(type);
-        if (
-          (type.child &&
-            typeObject.code === 'ARRAY' &&
-            typeObject.arrayElementType?.code !== 'TYPE_CODE_UNSPECIFIED') ||
-          (!type.child && typeObject.code !== 'TYPE_CODE_UNSPECIFIED')
-        ) {
-          paramTypes[param] = typeObject;
+        if (process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'] === 'true') {
+          const typeObject = codec.createTypeObject(type);
+          if (
+            (type.child &&
+              typeObject.code === 'ARRAY' &&
+              typeObject.arrayElementType?.code !== 'TYPE_CODE_UNSPECIFIED') ||
+            (!type.child && typeObject.code !== 'TYPE_CODE_UNSPECIFIED')
+          ) {
+            paramTypes[param] = typeObject;
+          }
+        } else {
+          paramTypes[param] = codec.createTypeObject(type);
         }
       });
     }

test/codec.ts

@@ -1778,12 +1778,41 @@ describe('codec', () => {
       });
     });
 
-    it('should determine if the uuid value is unspecified', () => {
+    it('should determine if the uuid value is string', () => {
       assert.deepStrictEqual(codec.getType(uuid.v4()), {
-        type: 'unspecified',
+        type: 'string',
       });
     });
 
+    it('should determine if the uuid value is unspecified when SPANNER_ENABLE_UUID_AS_UNTYPED is true', () => {
+      const emitWarningStub = sandbox.stub(process, 'emitWarning');
+      try {
+        process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'] = 'true';
+        assert.deepStrictEqual(codec.getType(uuid.v4()), {
+          type: 'unspecified',
+        });
+        assert.strictEqual(emitWarningStub.calledOnce, true);
+        assert.strictEqual(
+          emitWarningStub.firstCall.args[0],
+          'SPANNER_ENABLE_UUID_AS_UNTYPED environment variable is deprecated and will be removed in a future release.',
+        );
+      } finally {
+        delete process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'];
+        emitWarningStub.restore();
+      }
+    });
+
+    it('should determine if the uuid value is string when SPANNER_ENABLE_UUID_AS_UNTYPED is false', () => {
+      try {
+        process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'] = 'false';
+        assert.deepStrictEqual(codec.getType(uuid.v4()), {
+          type: 'string',
+        });
+      } finally {
+        delete process.env['SPANNER_ENABLE_UUID_AS_UNTYPED'];
+      }
+    });
+
     it('should determine if the value is a float32', () => {
       assert.deepStrictEqual(codec.getType(new codec.Float32(1.1)), {
         type: 'float32',