From be8996260fa6e5ea86ffa679c2fd3f872a887d7b Mon Sep 17 00:00:00 2001
From: Alessandro Palumbo <apalumbo@byte-code.com>
Date: Sat, 5 Oct 2019 09:09:12 +0200
Subject: [PATCH] feat(stepfunctions): Added test and validation for
 maxConcurrency, that has to be a positive integer

---
 .../aws-stepfunctions/lib/states/map.ts       | 26 ++++++++-
 .../aws-stepfunctions/test/test.map.ts        | 56 +++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/packages/@aws-cdk/aws-stepfunctions/lib/states/map.ts b/packages/@aws-cdk/aws-stepfunctions/lib/states/map.ts
index 826da6419708c..3500952bfe3f1 100644
--- a/packages/@aws-cdk/aws-stepfunctions/lib/states/map.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/lib/states/map.ts
@@ -80,7 +80,7 @@ export interface MapProps {
 export class Map extends State implements INextable {
     public readonly endStates: INextable[];
 
-    private readonly maxConcurrency?: number;
+    private readonly maxConcurrency: number | undefined;
     private readonly itemsPath?: string;
 
     constructor(scope: cdk.Construct, id: string, props: MapProps = {}) {
@@ -150,10 +150,30 @@ export class Map extends State implements INextable {
      * Validate this state
      */
     protected validate(): string[] {
+        const validateMaxConcurrency = () => {
+            const maxConcurrency = this.maxConcurrency;
+            if (maxConcurrency === undefined) {
+                return;
+            }
+
+            const isFloat = Math.floor(maxConcurrency) !== maxConcurrency;
+
+            const isNotPositiveInteger = maxConcurrency < 0 || maxConcurrency > Number.MAX_SAFE_INTEGER;
+
+            if (isFloat || isNotPositiveInteger) {
+                errors.push('maxConcurrency, if provided, has to be a positive integer');
+            }
+        };
+
+        const errors: string[] = [];
+
         if (!this.iteration) {
-            return ['Map state must have a non-empty iterator'];
+            errors.push('Map state must have a non-empty iterator');
         }
-        return [];
+
+        validateMaxConcurrency();
+
+        return errors;
     }
 
     private renderItemsPath(): any {
diff --git a/packages/@aws-cdk/aws-stepfunctions/test/test.map.ts b/packages/@aws-cdk/aws-stepfunctions/test/test.map.ts
index 1cdd9e2cabdc6..e6c66dca32945 100644
--- a/packages/@aws-cdk/aws-stepfunctions/test/test.map.ts
+++ b/packages/@aws-cdk/aws-stepfunctions/test/test.map.ts
@@ -73,6 +73,62 @@ export = {
             app.synth();
         }, /Map state must have a non-empty iterator/, 'A validation was expected');
 
+        test.done();
+    },
+    'synth fails when maxConcurrency is a float'(test: Test) {
+        test.throws(() => {
+            const app = new cdk.App();
+            const stack = new cdk.Stack(app, 'my-stack');
+
+            const map = new stepfunctions.Map(stack, 'Map State', {
+                maxConcurrency: 1.2,
+                itemsPath: stepfunctions.Data.stringAt('$.inputForMap')
+            });
+            map.iterator(new stepfunctions.Pass(stack, 'Pass State'));
+
+            new stepfunctions.StateGraph(map, 'Test Graph');
+
+            app.synth();
+        }, /maxConcurrency, if provided, has to be a positive integer/);
+
+        test.done();
+    },
+    'synth fails when maxConcurrency is a negative integer'(test: Test) {
+
+        test.throws(() => {
+            const app = new cdk.App();
+            const stack = new cdk.Stack(app, 'my-stack');
+
+            const map = new stepfunctions.Map(stack, 'Map State', {
+                maxConcurrency: -1,
+                itemsPath: stepfunctions.Data.stringAt('$.inputForMap')
+            });
+            map.iterator(new stepfunctions.Pass(stack, 'Pass State'));
+
+            new stepfunctions.StateGraph(map, 'Test Graph');
+
+            app.synth();
+        }, /maxConcurrency, if provided, has to be a positive integer/);
+
+        test.done();
+    },
+    'synth fails when maxConcurrency is too big to be an integer'(test: Test) {
+
+        const app = new cdk.App();
+        const stack = new cdk.Stack(app, 'my-stack');
+
+        const map = new stepfunctions.Map(stack, 'Map State', {
+            maxConcurrency: Number.MAX_VALUE,
+            itemsPath: stepfunctions.Data.stringAt('$.inputForMap')
+        });
+        map.iterator(new stepfunctions.Pass(stack, 'Pass State'));
+
+        new stepfunctions.StateGraph(map, 'Test Graph');
+
+        test.throws(() => {
+            app.synth();
+        }, /maxConcurrency, if provided, has to be a positive integer/);
+
         test.done();
     }
 };