diff --git a/packages/squiggle-lang/__tests__/SqError_test.res b/packages/squiggle-lang/__tests__/SqError_test.res
new file mode 100644
index 00000000..55109dde
--- /dev/null
+++ b/packages/squiggle-lang/__tests__/SqError_test.res
@@ -0,0 +1,41 @@
+open Jest
+open Expect
+
+describe("SqError.Message", () => {
+  test("toString", () =>
+    expect(SqError.Message.REOther("test error")->SqError.Message.toString)->toBe(
+      "Error: test error",
+    )
+  )
+})
+
+describe("SqError", () => {
+  test("fromMessage", () =>
+    expect(SqError.Message.REOther("test error")->SqError.fromMessage->SqError.toString)->toBe(
+      "Error: test error",
+    )
+  )
+
+  test("toStringWithStackTrace with empty stacktrace", () =>
+    expect(
+      SqError.Message.REOther("test error")->SqError.fromMessage->SqError.toStringWithStackTrace,
+    )->toBe("Error: test error")
+  )
+
+  test("toStringWithStackTrace", () => {
+    let frameStack =
+      Reducer_FrameStack.make()
+      ->Reducer_FrameStack.extend("frame1", None)
+      ->Reducer_FrameStack.extend("frame2", None)
+
+    expect(
+      SqError.Message.REOther("test error")
+      ->SqError.fromMessageWithFrameStack(frameStack)
+      ->SqError.toStringWithStackTrace,
+    )->toBe(`Error: test error
+Stack trace:
+  frame2
+  frame1
+`)
+  })
+})
diff --git a/packages/squiggle-lang/src/js/SqError.ts b/packages/squiggle-lang/src/js/SqError.ts
index a2bd1154..5c63d907 100644
--- a/packages/squiggle-lang/src/js/SqError.ts
+++ b/packages/squiggle-lang/src/js/SqError.ts
@@ -43,8 +43,6 @@ export class SqFrame {
   }
 
   location() {
-    console.log(RSFrameStack);
-    console.log(RSFrameStack.Frame);
     return RSFrameStack.Frame.getLocation(this._value);
   }
 }
diff --git a/packages/squiggle-lang/src/rescript/Reducer/Reducer_FrameStack.res b/packages/squiggle-lang/src/rescript/Reducer/Reducer_FrameStack.res
index a1dfd691..b7370e00 100644
--- a/packages/squiggle-lang/src/rescript/Reducer/Reducer_FrameStack.res
+++ b/packages/squiggle-lang/src/rescript/Reducer/Reducer_FrameStack.res
@@ -8,7 +8,7 @@ module Frame = {
     name ++
     switch location {
     | Some(location) =>
-      ` at line ${location.start.line->Js.Int.toString}, column ${location.start.column->Js.Int.toString}`
+      ` at line ${location.start.line->Js.Int.toString}, column ${location.start.column->Js.Int.toString}` // TODO - source id?
     | None => ""
     }
 
@@ -27,9 +27,11 @@ let extend = (t: t, name: string, location: option<Reducer_Peggy_Parse.location>
     location: location,
   })
 
+// this is useful for SyntaxErrors
 let makeSingleFrameStack = (location: Reducer_Peggy_Parse.location): t =>
   make()->extend(Reducer_T.topFrameName, Some(location))
 
+// this includes the left offset because it's mostly used in SqError.toStringWithStackTrace
 let toString = (t: t) =>
   t
   ->Belt.List.map(s => "  " ++ s->Frame.toString ++ "\n")