Merge branch 'master' into rds/mysql-8-export

packages/@aws-cdk/aws-iotevents/README.md

@@ -81,20 +81,20 @@ const coldState = new iotevents.State({
  stateName: 'cold',
 });
 
-// transit to coldState when temperature is 10
+// transit to coldState when temperature is less than 15
 warmState.transitionTo(coldState, {
  eventName: 'to_coldState', // optional property, default by combining the names of the States
- when: iotevents.Expression.eq(
+ when: iotevents.Expression.lt(
  iotevents.Expression.inputAttribute(input, 'payload.temperature'),
- iotevents.Expression.fromString('10'),
+ iotevents.Expression.fromString('15'),
  ),
  executing: [new actions.LambdaInvokeAction(func)], // optional
 });
-// transit to warmState when temperature is 20
+// transit to warmState when temperature is greater than or equal to 15
 coldState.transitionTo(warmState, {
- when: iotevents.Expression.eq(
+ when: iotevents.Expression.gte(
  iotevents.Expression.inputAttribute(input, 'payload.temperature'),
- iotevents.Expression.fromString('20'),
+ iotevents.Expression.fromString('15'),
  ),
 });
 

packages/@aws-cdk/aws-iotevents/lib/expression.ts

@@ -31,23 +31,71 @@ export abstract class Expression {
  * Create a expression for the Equal operator.
  */
  public static eq(left: Expression, right: Expression): Expression {
- return new BinaryOperationExpression(left, '==', right);
+ return new BinaryOperationExpression(left, '==', right, 9);
+ }
+
+ /**
+ * Create a expression for the Not Equal operator.
+ */
+ public static neq(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '!=', right, 9);
+ }
+
+ /**
+ * Create a expression for the Less Than operator.
+ */
+ public static lt(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '<', right, 10);
+ }
+
+ /**
+ * Create a expression for the Less Than Or Equal operator.
+ */
+ public static lte(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '<=', right, 10);
+ }
+
+ /**
+ * Create a expression for the Greater Than operator.
+ */
+ public static gt(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '>', right, 10);
+ }
+
+ /**
+ * Create a expression for the Greater Than Or Equal operator.
+ */
+ public static gte(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '>=', right, 10);
  }
 
  /**
  * Create a expression for the AND operator.
  */
  public static and(left: Expression, right: Expression): Expression {
- return new BinaryOperationExpression(left, '&&', right);
+ return new BinaryOperationExpression(left, '&&', right, 5);
+ }
+
+ /**
+ * Create a expression for the OR operator.
+ */
+ public static or(left: Expression, right: Expression): Expression {
+ return new BinaryOperationExpression(left, '||', right, 4);
  }
 
  constructor() {
  }
 
  /**
  * This is called to evaluate the expression.
+ *
+ * @param parentPriority priority of the parent of this expression,
+ * used for determining whether or not to add parenthesis around the expression.
+ * This is intended to be set according to MDN rules, see
+ * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#table
+ * for details
  */
- public abstract evaluate(): string;
+ public abstract evaluate(parentPriority?: number): string;
 }
 
 class StringExpression extends Expression {
@@ -65,11 +113,20 @@ class BinaryOperationExpression extends Expression {
  private readonly left: Expression,
  private readonly operator: string,
  private readonly right: Expression,
+ /**
+ * Indicates the priority of the operator.
+ * This is intended to be set according to MDN rules.
+ * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#table
+ */
+ private readonly priority: number,
  ) {
  super();
  }
 
- public evaluate() {
- return `${this.left.evaluate()} ${this.operator} ${this.right.evaluate()}`;
+ public evaluate(parentPriority?: number) {
+ const expression = `${this.left.evaluate(this.priority)} ${this.operator} ${this.right.evaluate(this.priority)}`;
+ return parentPriority === undefined || parentPriority <= this.priority
+ ? expression
+ : `(${expression})`;
  }
 }

packages/@aws-cdk/aws-iotevents/test/detector-model.test.ts

@@ -498,14 +498,30 @@ test('cannot create transitions that transit to duprecated target state', () =>
 });
 
 describe('Expression', () => {
- test('currentInput', () => {
+ const E = iotevents.Expression;
+ test.each([
+ ['currentInput', (testInput: iotevents.IInput) => E.currentInput(testInput), 'currentInput("test-input")'],
+ ['inputAttribute', (testInput: iotevents.IInput) => E.inputAttribute(testInput, 'json.path'), '$input.test-input.json.path'],
+ ['eq', () => E.eq(E.fromString('"aaa"'), E.fromString('"bbb"')), '"aaa" == "bbb"'],
+ ['neq', () => E.neq(E.fromString('"aaa"'), E.fromString('"bbb"')), '"aaa" != "bbb"'],
+ ['lt', () => E.lt(E.fromString('5'), E.fromString('2')), '5 < 2'],
+ ['lte', () => E.lte(E.fromString('5'), E.fromString('2')), '5 <= 2'],
+ ['gt', () => E.gt(E.fromString('5'), E.fromString('2')), '5 > 2'],
+ ['gte', () => E.gte(E.fromString('5'), E.fromString('2')), '5 >= 2'],
+ ['and', () => E.and(E.fromString('true'), E.fromString('false')), 'true && false'],
+ ['or', () => E.or(E.fromString('true'), E.fromString('false')), 'true || false'],
+ ['operator priority', () => E.and(
+ E.and(E.fromString('false'), E.fromString('false')),
+ E.or(E.fromString('true'), E.fromString('true')),
+ ), 'false && false && (true || true)'],
+ ])('%s', (_, getExpression, expectedCondition) => {
  // WHEN
  new iotevents.DetectorModel(stack, 'MyDetectorModel', {
  initialState: new iotevents.State({
  stateName: 'test-state',
  onEnter: [{
  eventName: 'test-eventName',
- condition: iotevents.Expression.currentInput(input),
+ condition: getExpression(input),
  }],
  }),
  });
@@ -517,97 +533,7 @@ describe('Expression', () => {
  Match.objectLike({
  OnEnter: {
  Events: [Match.objectLike({
- Condition: 'currentInput("test-input")',
- })],
- },
- }),
- ],
- },
- });
- });
-
- test('inputAttribute', () => {
- // WHEN
- new iotevents.DetectorModel(stack, 'MyDetectorModel', {
- initialState: new iotevents.State({
- stateName: 'test-state',
- onEnter: [{
- eventName: 'test-eventName',
- condition: iotevents.Expression.inputAttribute(input, 'json.path'),
- }],
- }),
- });
-
- // THEN
- Template.fromStack(stack).hasResourceProperties('AWS::IoTEvents::DetectorModel', {
- DetectorModelDefinition: {
- States: [
- Match.objectLike({
- OnEnter: {
- Events: [Match.objectLike({
- Condition: '$input.test-input.json.path',
- })],
- },
- }),
- ],
- },
- });
- });
-
- test('eq', () => {
- // WHEN
- new iotevents.DetectorModel(stack, 'MyDetectorModel', {
- initialState: new iotevents.State({
- stateName: 'test-state',
- onEnter: [{
- eventName: 'test-eventName',
- condition: iotevents.Expression.eq(
- iotevents.Expression.fromString('"aaa"'),
- iotevents.Expression.fromString('"bbb"'),
- ),
- }],
- }),
- });
-
- // THEN
- Template.fromStack(stack).hasResourceProperties('AWS::IoTEvents::DetectorModel', {
- DetectorModelDefinition: {
- States: [
- Match.objectLike({
- OnEnter: {
- Events: [Match.objectLike({
- Condition: '"aaa" == "bbb"',
- })],
- },
- }),
- ],
- },
- });
- });
-
- test('eq', () => {
- // WHEN
- new iotevents.DetectorModel(stack, 'MyDetectorModel', {
- initialState: new iotevents.State({
- stateName: 'test-state',
- onEnter: [{
- eventName: 'test-eventName',
- condition: iotevents.Expression.and(
- iotevents.Expression.fromString('true'),
- iotevents.Expression.fromString('false'),
- ),
- }],
- }),
- });
-
- // THEN
- Template.fromStack(stack).hasResourceProperties('AWS::IoTEvents::DetectorModel', {
- DetectorModelDefinition: {
- States: [
- Match.objectLike({
- OnEnter: {
- Events: [Match.objectLike({
- Condition: 'true && false',
+ Condition: expectedCondition,
  })],
  },
  }),