getSymbol docs and tests

Author: jmagaram

src/Core__Object.res

@@ -26,7 +26,20 @@
 */
 @get_index
 external get: ({..}, string) => option<'a> = ""
-@get_index external getSymbol: ({..}, Core__Symbol.t) => option<'a> = ""
+/**
+`getSymbol` gets the value of a property by symbol. Returns `None` if the property does not exist or has the value `undefined`. Otherwise returns `Some`, including if the value is `null`.
+
+## Examples
+
+```rescript
+let fruit = Symbol.make("fruit")
+let x = Object.empty()
+x->Object.setSymbol(fruit, "banana")
+x->Object.getSymbol(fruit) // Some("banana")
+```
+*/
+@get_index
+external getSymbol: ({..}, Core__Symbol.t) => option<'a> = ""
 @get_index external getSymbolUnsafe: ({..}, Core__Symbol.t) => 'a = ""
 
 @set_index external set: ({..}, string, 'a) => unit = ""

test/ObjectTests.mjs

@@ -112,8 +112,37 @@ runGetTest({
       ]
     });
 
+function getSymbolTestWhenExists(param) {
+  var obj = {};
+  var fruit = Symbol("fruit");
+  obj[fruit] = "banana";
+  var retrieved = obj[fruit];
+  Test.run([
+        [
+          "ObjectTests.res",
+          75,
+          15,
+          63
+        ],
+        "Object.getSymbol when exists return it as Some"
+      ], retrieved, eq, "banana");
+}
+
+getSymbolTestWhenExists(undefined);
+
+Test.run([
+      [
+        "ObjectTests.res",
+        84,
+        13,
+        65
+      ],
+      "Object.getSymbol when not exists return it as None"
+    ], ({})[Symbol("fruit")], eq, undefined);
+
 export {
   eq ,
   runGetTest ,
+  getSymbolTestWhenExists ,
 }
 /*  Not a pure module */

test/ObjectTests.res

@@ -63,3 +63,26 @@ let runGetTest = i =>
 //   get: i => i->Object.get("a")->Option.map(i => i->Array.concat([4, 5]))->Option.getWithDefault([]),
 //   expected: [],
 // }->runGetTest
+
+// ===== getSymbol =====
+
+let getSymbolTestWhenExists = () => {
+  let obj = Object.empty()
+  let fruit = Symbol.make("fruit")
+  obj->Object.setSymbol(fruit, "banana")
+  let retrieved = obj->Object.getSymbol(fruit)
+  Test.run(
+    __POS_OF__(`Object.getSymbol when exists return it as Some`),
+    retrieved,
+    eq,
+    Some("banana"),
+  )
+}
+getSymbolTestWhenExists()
+
+Test.run(
+  __POS_OF__(`Object.getSymbol when not exists return it as None`),
+  Object.empty()->Object.getSymbol(Symbol.make("fruit")),
+  eq,
+  None,
+)

test/TestSuite.mjs

@@ -33,6 +33,8 @@ var eq = ObjectTests.eq;
 
 var runGetTest = ObjectTests.runGetTest;
 
+var getSymbolTestWhenExists = ObjectTests.getSymbolTestWhenExists;
+
 export {
   bign ,
   TestError ,
@@ -47,5 +49,6 @@ export {
   $$catch ,
   eq ,
   runGetTest ,
+  getSymbolTestWhenExists ,
 }
 /* IntTests Not a pure module */