Support full-text index decorator in babel plugin (#6218)

* Support full-text index decorator in babel plugin

- Check for `index` decorator calls that are passed the string "full-text" and subsequently add the `{ indexed: "full-text" }` property to the schema.
- Update README with description and example of indexing a string field by full text
- Update tests to verify schemas with full-text indexing are properly generated

* Remove check for index decorator parameter

Removes check that the specific string "full-text" is the only allowable parameter to the `@index` decorator. New behavior is to allow any string to be passed through to the schema. Invalid values in the schema will throw at runtime, alerting user to possible errors.

packages/babel-plugin/README.md

@@ -206,10 +206,10 @@ Note that use of decorators requires using the `@babel/plugin-proposal-decorator
 
 This table shows the available decorators:
 
-| Decorator | Parameters                    | Notes                                                                                                |
-| --------- | ----------------------------- | ---------------------------------------------------------------------------------------------------- |
-| `index`   | none                          | Specifies that the decorated property should be indexed by Realm.                                    |
-| `mapTo`   | `(realmPropertyName: string)` | Specifies that the decorated property should be stored as `realmPropertyName` in the Realm database. |
+| Decorator | Parameters                    | Notes                                                                                                                                                                           |
+|-----------|-------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `index`   | none or `("full-text")`       | Specifies that the decorated property should be indexed by Realm. Providing the string "full-text" specifies that the property should be indexed for full-text search by Realm. |
+| `mapTo`   | `(realmPropertyName: string)` | Specifies that the decorated property should be stored as `realmPropertyName` in the Realm database.                                                                            |
 
 The example below shows both decorators in use:
 
@@ -219,8 +219,11 @@ import { mapTo, index } from "@realm/babel-plugin";
 
 export class Task extends Realm.Object {
   _id!: Realm.BSON.ObjectId;
-  // Add an index to the `description` property
+  // Add an index to the `assignee` property
   @index
+  assignee!: string;
+  // Specify that the `description` property should be indexed for full-text search
+  @index("full-text")
   description!: string;
   // Specify that the `isComplete` property should be stored as `complete` in the Realm database
   @mapTo("complete")

packages/babel-plugin/src/index.test.ts

@@ -390,6 +390,39 @@ describe("Babel plugin", () => {
       expect(transformCode).not.toContain("_applyDecoratedDescriptor");
     });
 
+    it('handles `@index("full-text")` decorators', () => {
+      const transformCode = transformProperty(`@index("full-text") name: Realm.Types.String;`);
+      const parsedSchema = extractSchema(transformCode);
+
+      expect((parsedSchema?.properties.name as PropertySchema).indexed).toEqual("full-text");
+    })
+
+    it('handles `@index("full-text")` decorators from the Realm import', () => {
+      const transformCode = transform({
+        source: `import Realm, { Types, BSON, List, Set, Dictionary, Mixed } from "realm";
+        export class Person extends Realm.Object { @Realm.index("full-text") name: Realm.Types.String; }`,
+      });
+      const parsedSchema = extractSchema(transformCode);
+
+      expect((parsedSchema?.properties.name as PropertySchema).indexed).toEqual("full-text");
+    });
+
+    it('ignores `@index("full-text")` decorators not imported from `realm`', () => {
+      const transformCode = transform({
+        source: `import Realm, { Types, BSON, List, Set, Dictionary, Mixed } from "realm";
+        export class Person extends Realm.Object { @index("full-text") name: Realm.Types.String; }`,
+      });
+      const parsedSchema = extractSchema(transformCode);
+
+      expect((parsedSchema?.properties.name as PropertySchema).indexed).toBeUndefined();
+    });
+
+    it('removes `@index("full-text")` decorators from the source', () => {
+      const transformCode = transformProperty(`@index("full-text") name: Realm.Types.String;`);
+      // This is what Babel outputs for transformed decorators
+      expect(transformCode).not.toContain("_applyDecoratedDescriptor");
+    });
+
     it("handles `@mapTo` decorators", () => {
       const transformCode = transformProperty(`@mapTo("rename") name: Realm.Types.String;`);
       const parsedSchema = extractSchema(transformCode);

packages/babel-plugin/src/plugin/index.ts

@@ -290,6 +290,13 @@ function visitRealmClassProperty(path: NodePath<types.ClassProperty>) {
   }
   const index = Boolean(indexDecorator);
 
+  const indexDecoratorCall = findDecoratorCall(decoratorsPath, "index");
+  const indexCall =
+    indexDecoratorCall
+      && types.isStringLiteral(indexDecoratorCall.callExpression.arguments[0])
+        ? indexDecoratorCall.callExpression.arguments[0].value
+        : undefined;
+
   const mapToDecorator = findDecoratorCall(decoratorsPath, "mapTo");
   const mapTo =
     mapToDecorator && types.isStringLiteral(mapToDecorator.callExpression.arguments[0])
@@ -299,6 +306,7 @@ function visitRealmClassProperty(path: NodePath<types.ClassProperty>) {
   // Remove the decorators from the final source as they are only for schema annotation purposes.
   // Decorator implementations will throw to prevent usage outside of the plugin.
   if (indexDecorator) indexDecorator.remove();
+  if (indexDecoratorCall) indexDecoratorCall.decoratorNode.remove();
   if (mapToDecorator) mapToDecorator.decoratorNode.remove();
 
   if (keyPath.isIdentifier()) {
@@ -336,6 +344,10 @@ function visitRealmClassProperty(path: NodePath<types.ClassProperty>) {
         properties.push(types.objectProperty(types.identifier("indexed"), types.booleanLiteral(true)));
       }
 
+      if (indexCall) {
+        properties.push(types.objectProperty(types.identifier("indexed"), types.stringLiteral(indexCall)))
+      }
+
       if (mapTo) {
         properties.push(types.objectProperty(types.identifier("mapTo"), types.stringLiteral(mapTo)));
       }