fix(lambda): cannot use latest version in multiple cloudfront distributions

packages/@aws-cdk/aws-lambda/lib/function-base.ts

@@ -194,6 +194,8 @@ export abstract class FunctionBase extends Resource implements IFunction {
    */
   protected _connections?: ec2.Connections;
 
+  private _latestVersion?: LatestVersion;
+
   /**
    * Adds a permission to the Lambda resource policy.
    * @param id The id ƒor the permission construct
@@ -244,8 +246,10 @@ export abstract class FunctionBase extends Resource implements IFunction {
   }
 
   public get latestVersion(): IVersion {
-    // Dynamic to avoid infinite recursion when creating the LatestVersion instance...
-    return new LatestVersion(this);
+    if (!this._latestVersion) {
+      this._latestVersion = new LatestVersion(this);
+    }
+    return this._latestVersion;
   }
 
   /**

packages/@aws-cdk/aws-lambda/test/test.function.ts

@@ -359,6 +359,31 @@ export = testCase({
     test.done();
   },
 
+  'multiple calls to latestVersion returns the same version'(test: Test) {
+    const stack = new cdk.Stack();
+
+    const fn = new lambda.Function(stack, 'MyLambda', {
+      code: new lambda.InlineCode('hello()'),
+      handler: 'index.hello',
+      runtime: lambda.Runtime.NODEJS_10_X,
+    });
+
+    const version1 = fn.latestVersion;
+    const version2 = fn.latestVersion;
+
+    const expectedArn = {
+      'Fn::Join': ['', [
+        { 'Fn::GetAtt': ['MyLambdaCCE802FB', 'Arn'] },
+        ':$LATEST',
+      ]],
+    };
+    test.equal(version1, version2);
+    test.deepEqual(stack.resolve(version1.functionArn), expectedArn);
+    test.deepEqual(stack.resolve(version2.functionArn), expectedArn);
+
+    test.done();
+  },
+
   'currentVersion': {
     // see test.function-hash.ts for more coverage for this
     'logical id of version is based on the function hash'(test: Test) {