unifying the messaging for type errors and adding type checks for builtin types (#10474)

* surface better type errors in pxsim

* cleanup

* make messages consistent

* add type checking for refaction

* move function

* fix action typecheck and null/undefined type string

* add errors for get/set/delete

Author: riknoll

pxtcompiler/emitter/backjs.ts

@@ -493,16 +493,19 @@ function ${id}(s) {
             }
         }
 
+        function vTableRef(info: ClassInfo) {
+            return `${info.id}_VT`
+        }
+
         function checkSubtype(info: ClassInfo, r0 = "r0") {
-            const vt = `${info.id}_VT`
-            return `checkSubtype(${r0}, ${vt})`
+            return `checkSubtype(${r0}, ${vTableRef(info)})`
         }
 
         function emitInstanceOf(info: ClassInfo, tp: string, r0 = "r0") {
             if (tp == "bool")
                 write(`r0 = ${checkSubtype(info)};`)
             else if (tp == "validate") {
-                write(`if (!${checkSubtype(info, r0)}) failedCast(${r0});`)
+                write(`if (!${checkSubtype(info, r0)}) failedCast(${r0}, ${vTableRef(info)});`)
             } else {
                 U.oops()
             }

pxtsim/langsupport.ts

@@ -531,6 +531,9 @@ namespace pxsim {
         }
 
         export function mapGetByString(map: RefMap, key: string) {
+            if (!map) {
+                throwFailedPropertyAccessError(map, key);
+            }
             key += ""
             if (map instanceof RefRecord) {
                 let r = map as RefRecord
@@ -544,8 +547,14 @@ namespace pxsim {
         }
 
         export function mapDeleteByString(map: RefMap, key: string) {
-            if (!(map instanceof RefMap))
-                pxtrt.panic(923)
+            if (map === undefined || map === null) {
+                throwNullUndefinedAsObjectError();
+            }
+
+            if (!(map instanceof RefMap)) {
+                throwFailedCastError(map, "object");
+            }
+
             let i = map.findIdx(key);
             if (i >= 0)
                 map.data.splice(i, 1)
@@ -556,6 +565,9 @@ namespace pxsim {
         export const mapGetGeneric = mapGetByString
 
         export function mapSetByString(map: RefMap, key: string, val: any) {
+            if (!map) {
+                throwFailedPropertyAccessError(map, key);
+            }
             key += ""
             if (map instanceof RefRecord) {
                 let r = map as RefRecord
@@ -574,6 +586,9 @@ namespace pxsim {
         }
 
         export function keysOf(v: RefMap) {
+            if (v === undefined || v === null) {
+                throwNullUndefinedAsObjectError();
+            }
             let r = new RefCollection()
             if (v instanceof RefMap)
                 for (let k of v.data) {
@@ -653,6 +668,7 @@ namespace pxsim {
         }
 
         export function runInBackground(a: RefAction) {
+            typeCheck(a);
             runtime.runFiberAsync(a);
         }
 
@@ -662,10 +678,14 @@ namespace pxsim {
                     .then(() => U.delay(20))
                     .then(loop);
             }
-            pxtrt.nullCheck(a)
+            typeCheck(a);
             loop()
         }
-    }
-
 
+        export function typeCheck(a: RefAction) {
+            if (!a || !(a instanceof RefAction) && !(a as any).info) {
+                throwFailedCastError(a, "function");
+            }
+        }
+    }
 }