xpath: support for indexed-repeat function

.changeset/rotten-turtles-tease.md

@@ -0,0 +1,6 @@
+---
+'@getodk/scenario': minor
+'@getodk/xpath': minor
+---
+
+Support for `indexed-repeat` XPath function

packages/scenario/src/jr/Scenario.ts

@@ -143,7 +143,9 @@ export class Scenario {
 	readonly formName: string;
 	readonly instanceRoot: RootNode;
 
-	private readonly getPositionalEvents: Accessor<PositionalEvents>;
+	protected readonly getPositionalEvents: Accessor<PositionalEvents>;
+
+	protected readonly getEventPosition: Accessor<number>;
 	private readonly setEventPosition: Setter<number>;
 
 	protected readonly getSelectedPositionalEvent: Accessor<AnyPositionalEvent>;
@@ -154,14 +156,15 @@ export class Scenario {
 		this.formName = formName;
 		this.instanceRoot = instanceRoot;
 
-		const [eventPosition, setEventPosition] = createSignal(0);
+		const [getEventPosition, setEventPosition] = createSignal(0);
 
 		this.getPositionalEvents = () => getPositionalEvents(instanceRoot);
+		this.getEventPosition = getEventPosition;
 		this.setEventPosition = setEventPosition;
 
 		this.getSelectedPositionalEvent = createMemo(() => {
 			const events = getPositionalEvents(instanceRoot);
-			const position = eventPosition();
+			const position = getEventPosition();
 			const event = events[position];
 
 			if (event == null) {
@@ -386,7 +389,7 @@ export class Scenario {
 		const node = getNodeForReference(this.instanceRoot, reference);
 
 		if (node == null) {
-			throw new Error(`No "answer" node for reference: ${reference}`);
+			throw new Error(`No instance node for reference: ${reference}`);
 		}
 
 		return node;

packages/scenario/test/repeat.test.ts

@@ -2068,133 +2068,6 @@ describe('Tests ported from JavaRosa - repeats', () => {
 		});
 	});
 
-	describe('IndexedRepeatRelativeRefsTest.java', () => {
-		const ABSOLUTE_TARGET = '/data/some-group/item/value';
-		const RELATIVE_TARGET = '../item/value';
-		const ABSOLUTE_GROUP = '/data/some-group/item';
-		const RELATIVE_GROUP = '../item';
-		const ABSOLUTE_INDEX = '/data/total-items';
-		const RELATIVE_INDEX = '../../total-items';
-
-		interface IndexedRepeatRelativeRefsOptions {
-			readonly testName: string;
-			readonly target: string;
-			readonly group: string;
-			readonly index: string;
-		}
-
-		const parameters: readonly IndexedRepeatRelativeRefsOptions[] = [
-			{
-				testName: 'Target: absolute, group: absolute, index: absolute',
-				target: ABSOLUTE_TARGET,
-				group: ABSOLUTE_GROUP,
-				index: ABSOLUTE_INDEX,
-			},
-			{
-				testName: 'Target: absolute, group: absolute, index: relative',
-				target: ABSOLUTE_TARGET,
-				group: ABSOLUTE_GROUP,
-				index: RELATIVE_INDEX,
-			},
-			{
-				testName: 'Target: absolute, group: relative, index: absolute',
-				target: ABSOLUTE_TARGET,
-				group: RELATIVE_GROUP,
-				index: ABSOLUTE_INDEX,
-			},
-			{
-				testName: 'Target: absolute, group: relative, index: relative',
-				target: ABSOLUTE_TARGET,
-				group: RELATIVE_GROUP,
-				index: RELATIVE_INDEX,
-			},
-			{
-				testName: 'Target: relative, group: absolute, index: absolute',
-				target: RELATIVE_TARGET,
-				group: ABSOLUTE_GROUP,
-				index: ABSOLUTE_INDEX,
-			},
-			{
-				testName: 'Target: relative, group: absolute, index: relative',
-				target: RELATIVE_TARGET,
-				group: ABSOLUTE_GROUP,
-				index: RELATIVE_INDEX,
-			},
-			{
-				testName: 'Target: relative, group: relative, index: absolute',
-				target: RELATIVE_TARGET,
-				group: RELATIVE_GROUP,
-				index: ABSOLUTE_INDEX,
-			},
-			{
-				testName: 'Target: relative, group: relative, index: relative',
-				target: RELATIVE_TARGET,
-				group: RELATIVE_GROUP,
-				index: RELATIVE_INDEX,
-			},
-		];
-
-		/**
-		 * **PORTING NOTES**
-		 *
-		 * - Fails pending implementation of `indexed-repeat` XPath function.
-		 *
-		 * - Parameters adapted to match values in JavaRosa. Note that the
-		 *   parameters are passed as {@link options} rather than destructured. Java
-		 *   lets you reference `group` (the class property) and `group` (the
-		 *   imported static method) in the same scope. TypeScript/JavaScript don't
-		 *   let you do that... which is fine, because doing that is really weird!
-		 */
-		it.fails.each<IndexedRepeatRelativeRefsOptions>(parameters)('$testName', async (options) => {
-			const scenario = await Scenario.init(
-				'Some form',
-				html(
-					head(
-						title('Some form'),
-						model(
-							mainInstance(
-								t(
-									'data id="some-form"',
-									t('some-group', t('item jr:template=""', t('value')), t('last-value')),
-									t('total-items')
-								)
-							),
-							bind(ABSOLUTE_TARGET).type('int'),
-							bind('/data/total-items').type('int').calculate('count(/data/some-group/item)'),
-							bind('/data/some-group/last-value')
-								.type('int')
-								.calculate(
-									'indexed-repeat(' +
-										options.target +
-										', ' +
-										options.group +
-										', ' +
-										options.index +
-										')'
-								)
-						)
-					),
-					body(
-						group(
-							'/data/some-group',
-							group(
-								'/data/some-group/item',
-								repeat('/data/some-group/item', input('/data/some-group/item/value'))
-							)
-						)
-					)
-				)
-			);
-
-			scenario.answer('/data/some-group[1]/item[1]/value', 11);
-			scenario.answer('/data/some-group[1]/item[2]/value', 22);
-			scenario.answer('/data/some-group[1]/item[3]/value', 33);
-
-			expect(scenario.answerOf('/data/total-items')).toEqualAnswer(intAnswer(3));
-			expect(scenario.answerOf('/data/some-group/last-value')).toEqualAnswer(intAnswer(33));
-		});
-	});
-
 	describe('TriggersForRelativeRefsTest.java (regression tests)', () => {
 		describe('indefinite repeat `jr:count` expression', () => {
 			/**

packages/scenario/test/smoketests/child-vaccination.test.ts

@@ -12,6 +12,17 @@ import type {
 } from '../../src/jr/event/getPositionalEvents.ts';
 import { JRTreeReference as BaseJRTreeReference } from '../../src/jr/xpath/JRTreeReference.ts';
 
+/**
+ * Intentionally naive. The scope of expressions we expect to handle in this
+ * test suite is narrow enough that we don't need to do more robust static
+ * analysis and serialization. There is more complete logic in
+ * `@getodk/xforms-engine` to do this, but it's intentionally project-private
+ * (at least it is at time of writing).
+ */
+const naiveStripPositionalPredicates = (expression: string): string => {
+	return expression.replaceAll(/\[\d+\]/g, '');
+};
+
 /**
  * **PORTING NOTES**
  *
@@ -54,7 +65,9 @@ const refSingletons = new UpsertableMap<string, JRTreeReference>();
 
 class JRTreeReference extends BaseJRTreeReference {
 	genericize(): JRTreeReference {
-		throw new IncompleteTestPortError('TreeReference.genericize');
+		const reference = naiveStripPositionalPredicates(this.xpathReference);
+
+		return new JRTreeReference(reference);
 	}
 
 	equals(other: JRTreeReference): boolean {
@@ -123,6 +136,24 @@ class Scenario extends BaseScenario {
 		/* eslint-enable no-console */
 	}
 
+	private getNextEventPosition(): AnyPositionalEvent {
+		const currentPosition = this.getSelectedPositionalEvent();
+
+		if (currentPosition.eventType === 'END_OF_FORM') {
+			throw 'todo';
+		}
+
+		const events = this.getPositionalEvents();
+		const position = this.getEventPosition();
+		const next = events[position + 1];
+
+		if (next == null) {
+			throw new Error(`No question at position: ${position}`);
+		}
+
+		return next;
+	}
+
 	/**
 	 * @deprecated
 	 *
@@ -142,7 +173,13 @@ class Scenario extends BaseScenario {
 	 * increased clarity of intent.
 	 */
 	nextRef(): JRTreeReference {
-		throw new IncompleteTestPortError('Extended Scenario.nextRef');
+		const next = this.getNextEventPosition();
+
+		if (next.eventType === 'END_OF_FORM') {
+			throw 'todo';
+		}
+
+		return new JRTreeReference(next.node.currentState.reference);
 	}
 
 	/**
@@ -549,42 +586,32 @@ describe('ChildVaccinationTest.java', () => {
 	});
 
 	it.fails('[smoke test]', async () => {
-		let scenario: Scenario | null = null;
+		const scenario = await Scenario.init('child_vaccination_VOL_tool_v12.xml');
 
-		try {
-			scenario = await Scenario.init('child_vaccination_VOL_tool_v12.xml');
-
-			expect.fail('Update `child-vaccination.test.ts`, known failure mode has changed');
-		} catch (error) {
-			expect(error).toBeInstanceOf(Error);
+		scenario.next('/data/building_type');
+		scenario.answer('multi');
+		scenario.next('/data/not_single');
+		scenario.next('/data/not_single/gps');
+		scenario.answer('1.234 5.678');
+		scenario.next('/data/building_name');
+		scenario.answer('Some building');
+		scenario.next('/data/full_address1');
+		scenario.answer('Some address, some location');
 
-			// Failure of this assertion likely means that we've implemented the
-			// `indexed-repeat` XPath function. When that occurs, these error
-			// condition assertions should be removed, and the `Scenario.init` call
-			// should be treated normally.
-			//
-			// If a new failure occurs after that point, and that failure cannot be
-			// addressed by updating the test to be more complete (e.g. by specifying
-			// more of the expected references in `scenario.next` calls, or
-			// implementing other aspects of the test which are currently deferred),
-			// consider adding a similar function/assertion/comment to this effect,
-			// asserting that new known failure condition and prompting the test to be
-			// updated again once it is resolved.
-			expect((error as Error).message).toContain('function not defined: indexed-repeat');
-		}
+		// endregion
 
-		if (scenario == null) {
-			return;
-		}
+		const currentExpectedPointOfFailure = () => {
+			expect(scenario.answerOf('/data/household_count').toString()).toBe('2');
 
-		scenario.next('/data/building_type');
+			const secondHouseholdControlledByRepeatCount = scenario.getInstanceNode('/data/household[2]');
 
-		const currentExpectedPointOfFailure = () => {
-			scenario.answer('multi');
+			expect(secondHouseholdControlledByRepeatCount).not.toBeNull();
 		};
 
 		try {
-			expect(currentExpectedPointOfFailure).toThrowError('function not defined: indexed-repeat');
+			expect(currentExpectedPointOfFailure).toThrowError(
+				'No instance node for reference: /data/household[2]'
+			);
 
 			if (typeof currentExpectedPointOfFailure === 'function') {
 				scenario.trace(
@@ -593,20 +620,21 @@ describe('ChildVaccinationTest.java', () => {
 
 				return;
 			}
-		} catch {
-			throw new Error();
-		}
+		} catch (error) {
+			// Failure of this assertion likely means that we've implemented
+			// `jr:count`. When that occurs, these error condition assertions should
+			// be removed, and the test should be updated to add expected node-set
+			// reference assertions in the `scenario.next` calls, and so on, either
+			// until the test passes or a new known point of failure is identified.
 
-		scenario.answer('multi');
-		scenario.next('/data/not_single');
-		scenario.next('/data/not_single/gps');
-		scenario.answer('1.234 5.678');
-		scenario.next('/data/building_name');
-		scenario.answer('Some building');
-		scenario.next('/data/full_address1');
-		scenario.answer('Some address, some location');
+			expect(error).toBeInstanceOf(Error);
 
-		// endregion
+			const { message } = error as Error;
+
+			expect.fail(
+				`Update \`child-vaccination.test.ts\`, known failure mode has changed: ${message}`
+			);
+		}
 
 		// region Answer all household repeats