Add panic function (#72)

* feat(error): add panic/Error.panic

refactor(error): less magic needed

Co-authored-by: Christoph Knittel <[email protected]>

docs(error): panic fixes

Co-authored-by: Christoph Knittel <[email protected]>

docs(error): ReScript, not OCaml

* test(error): test panic

* docs(changelog): update changelog for panic/Error.panic

* docs(changelog): adjust panic entry after splitting PR

Co-authored-by: Christoph Knittel <[email protected]>

---------

Co-authored-by: Christoph Knittel <[email protected]>

Author: glennsl

Diff for: CHANGELOG.md

@@ -22,6 +22,7 @@
 - Add `make`, `fromInitializer`, `findMap`, `keepSome`, `reduceRight` and `reduceRightWithIndex`. https://github.com/rescript-association/rescript-core/pull/49
 - Remove `reduceReverse` in favor of `reduceRight`. https://github.com/rescript-association/rescript-core/pull/49
 - Fixed type signatures of `reduce` and `reduceWithIndex`. https://github.com/rescript-association/rescript-core/pull/49
+- Add `panic`/`Error.panic`. https://github.com/rescript-association/rescript-core/pull/72
 
 ### Documentation
 

Diff for: src/Core__Error.mjs

@@ -13,12 +13,17 @@ var $$TypeError = {};
 
 var $$URIError = {};
 
+function panic(msg) {
+  throw new Error("Panic! " + msg);
+}
+
 export {
   $$EvalError ,
   $$RangeError ,
   $$ReferenceError ,
   $$SyntaxError ,
   $$TypeError ,
   $$URIError ,
+  panic ,
 }
 /* No side effect */

Diff for: src/Core__Error.res

@@ -35,3 +35,5 @@ module URIError = {
 }
 
 external raise: t => 'a = "%raise"
+
+let panic = msg => make(j`Panic! $msg`)->raise

Diff for: src/Core__Error.resi

@@ -155,3 +155,17 @@ if 5 > 10 {
 ```
 */
 external raise: t => 'a = "%raise"
+
+/**
+Raises a panic exception with the given message.
+
+A panic exception is a native JavaScript exception that is not intended to be caught and
+handled. Compared to a ReScript exception this will give a better stack trace and
+debugging experience.
+
+## Examples
+```rescript
+Error.panic("Uh oh. This was unexpected!")
+```
+*/
+let panic: string => 'a

Diff for: src/RescriptCore.mjs

@@ -1,5 +1,6 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
+import * as Core__Error from "./Core__Error.mjs";
 
 var $$Array;
 
@@ -93,6 +94,8 @@ var List;
 
 var Result;
 
+var panic = Core__Error.panic;
+
 export {
   $$Array ,
   Console ,
@@ -140,5 +143,6 @@ export {
   $$Option ,
   List ,
   Result ,
+  panic ,
 }
 /* No side effect */

Diff for: src/RescriptCore.res

@@ -65,3 +65,5 @@ type null<+'a> = Js.null<'a>
 type undefined<+'a> = Js.undefined<'a>
 
 type nullable<+'a> = Js.nullable<'a>
+
+let panic = Core__Error.panic

Diff for: test/ErrorTests.mjs

@@ -0,0 +1,39 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+
+import * as Test from "./Test.mjs";
+import * as Js_exn from "rescript/lib/es6/js_exn.js";
+import * as RescriptCore from "../src/RescriptCore.mjs";
+import * as Caml_js_exceptions from "rescript/lib/es6/caml_js_exceptions.js";
+
+function panicTest(param) {
+  var caught;
+  try {
+    caught = RescriptCore.panic("uh oh");
+  }
+  catch (raw_err){
+    var err = Caml_js_exceptions.internalToOCamlException(raw_err);
+    if (err.RE_EXN_ID === Js_exn.$$Error) {
+      caught = err._1.message;
+    } else {
+      throw err;
+    }
+  }
+  Test.run([
+        [
+          "ErrorTests.res",
+          8,
+          22,
+          43
+        ],
+        "Should resolve test"
+      ], caught, (function (prim0, prim1) {
+          return prim0 === prim1;
+        }), "Panic! uh oh");
+}
+
+panicTest(undefined);
+
+export {
+  panicTest ,
+}
+/*  Not a pure module */

Diff for: test/ErrorTests.res

@@ -0,0 +1,11 @@
+open RescriptCore
+
+let panicTest = () => {
+  let caught = try panic("uh oh") catch {
+  | Exn.Error(err) => Error.message(err)
+  }
+
+  Test.run(__POS_OF__("Should resolve test"), caught, \"==", Some("Panic! uh oh"))
+}
+
+panicTest()

Diff for: test/TestSuite.mjs

@@ -1,5 +1,6 @@
 // Generated by ReScript, PLEASE EDIT WITH CARE
 
+import * as ErrorTests from "./ErrorTests.mjs";
 import * as ArrayTests from "./ArrayTests.mjs";
 import * as PromiseTest from "./PromiseTest.mjs";
 
@@ -19,6 +20,8 @@ var Catching = PromiseTest.Catching;
 
 var Concurrently = PromiseTest.Concurrently;
 
+var panicTest = ErrorTests.panicTest;
+
 var eq = ArrayTests.eq;
 
 export {
@@ -30,6 +33,7 @@ export {
   Rejection ,
   Catching ,
   Concurrently ,
+  panicTest ,
   eq ,
 }
 /* ArrayTests Not a pure module */

Diff for: test/TestSuite.res

@@ -1,2 +1,3 @@
 include PromiseTest
+include ErrorTests
 include ArrayTests