From ffe0ca7d7f47dc11d8912b11daa388e66be358bb Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Mon, 18 Mar 2019 12:56:42 +0100
Subject: [PATCH] Issue 95: Improve error message when trying to call a
 non-callable.

---
 jsdate.c | 2 +-
 jsrun.c  | 6 +++---
 mujs.h   | 1 +
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/jsdate.c b/jsdate.c
index 5313250..9216c44 100644
--- a/jsdate.c
+++ b/jsdate.c
@@ -741,7 +741,7 @@ static void Dp_toJSON(js_State *J)
 
 	js_getproperty(J, 0, "toISOString");
 	if (!js_iscallable(J, -1))
-		js_typeerror(J, "Date.prototype.toJSON: this.toISOString not a function");
+		js_typeerror(J, "this.toISOString is not a function");
 	js_copy(J, 0);
 	js_call(J, 0);
 }
diff --git a/jsrun.c b/jsrun.c
index 49e08b5..6474a7f 100644
--- a/jsrun.c
+++ b/jsrun.c
@@ -230,7 +230,7 @@ int js_iserror(js_State *J, int idx)
 	return v->type == JS_TOBJECT && v->u.object->type == JS_CERROR;
 }
 
-static const char *js_typeof(js_State *J, int idx)
+const char *js_typeof(js_State *J, int idx)
 {
 	js_Value *v = stackidx(J, idx);
 	switch (v->type) {
@@ -1056,7 +1056,7 @@ void js_call(js_State *J, int n)
 	int savebot;
 
 	if (!js_iscallable(J, -n-2))
-		js_typeerror(J, "called object is not a function");
+		js_typeerror(J, "%s is not callable", js_typeof(J, -n-2));
 
 	obj = js_toobject(J, -n-2);
 
@@ -1090,7 +1090,7 @@ void js_construct(js_State *J, int n)
 	js_Object *newobj;
 
 	if (!js_iscallable(J, -n-1))
-		js_typeerror(J, "called object is not a function");
+		js_typeerror(J, "%s is not callable", js_typeof(J, -n-1));
 
 	obj = js_toobject(J, -n-1);
 
diff --git a/mujs.h b/mujs.h
index d5dcc93..7c133dd 100644
--- a/mujs.h
+++ b/mujs.h
@@ -213,6 +213,7 @@ int js_compare(js_State *J, int *okay);
 int js_equal(js_State *J);
 int js_strictequal(js_State *J);
 int js_instanceof(js_State *J);
+const char *js_typeof(js_State *J, int idx);
 
 #ifdef __cplusplus
 }