From 001e8745bb595991bc7310aea49e266dd6441cd1 Mon Sep 17 00:00:00 2001
From: sedinkinya <yury.sedinkin@nih.gov>
Date: Tue, 21 Jan 2025 16:12:29 -0500
Subject: [PATCH] Async boolean bug

LF-3224
---
 CHANGELOG.md                 |  5 +++++
 package-lock.json            |  4 ++--
 package.json                 |  2 +-
 src/fhirpath.js              |  5 ++++-
 test/async-functions.test.js | 34 ++++++++++++++++++++++++++++++----
 5 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bbc1649..da853d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,11 @@
 This log documents significant changes for each release.  This project follows
 [Semantic Versioning](http://semver.org/).
 
+## [3.16.3] - 2025-01-21
+### Fixed
+- Bug with async boolean expressions (when an operator takes an async value as
+  a singleton parameter).
+
 ## [3.16.2] - 2025-01-16
 ### Fixed
 - Bug with toString when userInvocationTable passed.
diff --git a/package-lock.json b/package-lock.json
index 766823c..a0fdca0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "fhirpath",
-  "version": "3.16.2",
+  "version": "3.16.3",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "fhirpath",
-      "version": "3.16.2",
+      "version": "3.16.3",
       "hasInstallScript": true,
       "license": "SEE LICENSE in LICENSE.md",
       "dependencies": {
diff --git a/package.json b/package.json
index f7d462e..dc4120f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "fhirpath",
-  "version": "3.16.2",
+  "version": "3.16.3",
   "description": "A FHIRPath engine",
   "main": "src/fhirpath.js",
   "types": "src/fhirpath.d.ts",
diff --git a/src/fhirpath.js b/src/fhirpath.js
index 66fba29..af87540 100644
--- a/src/fhirpath.js
+++ b/src/fhirpath.js
@@ -502,7 +502,10 @@ function makeParam(ctx, parentData, type, param) {
       }
     }
   }
-  return misc.singleton(res, type);
+
+  return res instanceof Promise ?
+    res.then(r => misc.singleton(r, type)) :
+    misc.singleton(res, type);
 }
 
 function doInvoke(ctx, fnName, data, rawParams){
diff --git a/test/async-functions.test.js b/test/async-functions.test.js
index 82f3416..b8b0c72 100644
--- a/test/async-functions.test.js
+++ b/test/async-functions.test.js
@@ -24,12 +24,11 @@ function mockFetchResults(results) {
 }
 
 describe('Async functions', () => {
+  afterEach(() => {
+    fetchSpy?.mockRestore();
+  })
 
   describe('%terminologies.validateVS', () => {
-    afterEach(() => {
-      fetchSpy?.mockRestore();
-    })
-
     it('should work ', (done) => {
       mockFetchResults([
         [/code=29463-7/, {
@@ -305,6 +304,33 @@ describe('Async functions', () => {
       );
       expect(result).toThrow('The asynchronous function "memberOf" is not allowed. To enable asynchronous functions, use the async=true or async="always" option.');
     });
+
+    it('should correctly process an async result in a boolean expression (when it is a singleton parameter)', (done) => {
+      mockFetchResults([
+        [/ValueSet\/\$validate-code/, {
+          "resourceType": "Parameters",
+          "parameter": [
+            {
+              "name": "result",
+              "valueBoolean": true
+            }
+          ]
+        }]
+      ]);
+      let result = fhirpath.evaluate(
+        resource,
+        "Observation.code.memberOf('http://hl7.org/fhir/ValueSet/observation-vitalsignresult') or false",
+        {},
+        model,
+        { async: true, terminologyUrl: "https://lforms-fhir.nlm.nih.gov/baseR4" }
+      );
+      expect(result instanceof Promise).toBe(true);
+      result.then((r) => {
+        expect(r).toEqual([true]);
+        done();
+      })
+    });
+
   });
 
   it('should be a conversion of the result to a Promise when option async is set to "always"', (done) => {