Add RegExp.flags external and corresponding tests (#7461)

* Add RegExp.flags external and corresponding tests

* fix tests

* changelog

---------

Co-authored-by: Gabriel Nordeborn <gabbe.nord@gmail.com>

Author: jmagaram

CHANGELOG.md

@@ -12,6 +12,10 @@
 
 # 12.0.0-alpha.14 (Unreleased)
 
+#### :rocket: New Feature
+
+- Add `RegExp.flags`. https://github.com/rescript-lang/rescript/pull/7461
+
 #### :bug: Bug fix
 
 - `rescript-tools doc` no longer includes shadowed bindings in its output. https://github.com/rescript-lang/rescript/pull/7497

runtime/Stdlib_RegExp.res

@@ -23,5 +23,6 @@ module Result = {
 @get external source: t => string = "source"
 @get external sticky: t => bool = "sticky"
 @get external unicode: t => bool = "unicode"
+@get external flags: t => string = "flags"
 
 external ignore: t => unit = "%ignore"

runtime/Stdlib_RegExp.resi

@@ -299,6 +299,20 @@ Console.log(regexp2->RegExp.unicode) // Logs `true`, since `u` is set
 @get
 external unicode: t => bool = "unicode"
 
+/**
+`flags(regexp)` returns a string consisting of all the flags set on this `RegExp`.
+
+See [`RegExp.flags`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/flags) on MDN.
+
+## Examples
+```rescript
+let regexp = RegExp.fromString("\\w+", ~flags="gi")
+Console.log(regexp->RegExp.flags) // Logs "gi", all the flags set on the RegExp
+```
+*/
+@get
+external flags: t => string = "flags"
+
 /**
   `ignore(regExp)` ignores the provided regExp and returns unit.
 

tests/tests/src/core/Core_RegExpTest.mjs

@@ -0,0 +1,41 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+
+import * as Test from "./Test.mjs";
+import * as Primitive_object from "rescript/lib/es6/Primitive_object.js";
+
+let eq = Primitive_object.equal;
+
+Test.run([
+  [
+    "Core_RegExpTest.res",
+    5,
+    13,
+    33
+  ],
+  "RegExp.flags basic"
+], new RegExp("\\w+", "gi").flags, eq, "gi");
+
+Test.run([
+  [
+    "Core_RegExpTest.res",
+    13,
+    13,
+    35
+  ],
+  "RegExp.flags sorting"
+], new RegExp("\\w+", "igd").flags, eq, "dgi");
+
+Test.run([
+  [
+    "Core_RegExpTest.res",
+    20,
+    20,
+    40
+  ],
+  "RegExp.flags empty"
+], new RegExp("\\w+").flags, eq, "");
+
+export {
+  eq,
+}
+/*  Not a pure module */

tests/tests/src/core/Core_RegExpTest.res

@@ -0,0 +1,20 @@
+let eq = (a, b) => a == b
+
+// Test for RegExp.flags
+Test.run(
+  __POS_OF__("RegExp.flags basic"),
+  RegExp.fromStringWithFlags("\\w+", ~flags="gi")->RegExp.flags,
+  eq,
+  "gi",
+)
+
+// Test for alphabetical sorting of flags
+Test.run(
+  __POS_OF__("RegExp.flags sorting"),
+  RegExp.fromStringWithFlags("\\w+", ~flags="igd")->RegExp.flags,
+  eq,
+  "dgi",
+)
+
+// Test with no flags
+Test.run(__POS_OF__("RegExp.flags empty"), RegExp.fromString("\\w+")->RegExp.flags, eq, "")

tests/tests/src/core/Core_TestSuite.mjs

@@ -7,6 +7,7 @@ import * as Core_TestTests from "./Core_TestTests.mjs";
 import * as Core_ArrayTests from "./Core_ArrayTests.mjs";
 import * as Core_ErrorTests from "./Core_ErrorTests.mjs";
 import * as Core_FloatTests from "./Core_FloatTests.mjs";
+import * as Core_RegExpTest from "./Core_RegExpTest.mjs";
 import * as Core_ObjectTests from "./Core_ObjectTests.mjs";
 import * as Core_PromiseTest from "./Core_PromiseTest.mjs";
 import * as Core_ResultTests from "./Core_ResultTests.mjs";
@@ -84,8 +85,6 @@ let PatternMatching = Core_DictTests.PatternMatching;
 
 let Has = Core_DictTests.Has;
 
-let eq = Core_IteratorTests.eq;
-
 let iterator = Core_IteratorTests.iterator;
 
 let syncResult = Core_IteratorTests.syncResult;
@@ -94,6 +93,8 @@ let asyncResult = Core_IteratorTests.asyncResult;
 
 let asyncIterator = Core_IteratorTests.asyncIterator;
 
+let eq = Core_RegExpTest.eq;
+
 export {
   bign,
   TestError,
@@ -130,10 +131,10 @@ export {
   intDict,
   PatternMatching,
   Has,
-  eq,
   iterator,
   syncResult,
   asyncResult,
   asyncIterator,
+  eq,
 }
 /* Core_IntTests Not a pure module */

tests/tests/src/core/Core_TestSuite.res

@@ -11,3 +11,4 @@ include Core_JsonTests
 include Core_NullableTests
 include Core_DictTests
 include Core_IteratorTests
+include Core_RegExpTest