prettyPrint: do not call legacy toString for Uint8Arrays

Certain Uint8Arrays returned from introspected functions fail to print with the pretty printer and log deprecated warnings.

This is because for those Uint8Arrays we override its toString as a compatibility shim to warn users of legacy behaviour. However, this makes its toString own property nonstandard.

Detect TypedArrays explicitly when pretty printing so it can be printed in an array-like format.

Fixes https://gitlab.gnome.org/GNOME/gjs/-/issues/434

Author: garyli2

installed-tests/js/testPrint.js

@@ -4,6 +4,7 @@
 
 imports.gi.versions.Gdk = '3.0';
 const Gdk = imports.gi.Gdk;
+const ByteArray = imports.byteArray;
 const {getPrettyPrintFunction} = imports._print;
 let prettyPrint = getPrettyPrintFunction(globalThis);
 
@@ -211,4 +212,38 @@ describe('prettyPrint', function () {
         expect(prettyPrint({'foo': imports}))
             .toEqual('{ foo: [GjsFileImporter root] }');
     });
+
+    describe('TypedArrays', () => {
+        [
+            Int8Array,
+            Uint8Array,
+            Uint16Array,
+            Uint8ClampedArray,
+            Int16Array,
+            Uint16Array,
+            Int32Array,
+            Uint32Array,
+            Float32Array,
+            Float64Array,
+        ].forEach(constructor => {
+            it(constructor.name, function () {
+                const arr = new constructor([1, 2, 3]);
+                expect(prettyPrint(arr))
+                    .toEqual('[1, 2, 3]');
+            });
+        });
+
+        [BigInt64Array, BigUint64Array].forEach(constructor => {
+            it(constructor.name, function () {
+                const arr = new constructor([1n, 2n, 3n]);
+                expect(prettyPrint(arr))
+                    .toEqual('[1, 2, 3]');
+            });
+        });
+    });
+
+    it('Uint8Array returned from introspected function', function () {
+        let a = ByteArray.fromString('⅜');
+        expect(prettyPrint(a)).toEqual('[226, 133, 156]');
+    });
 });

modules/script/_bootstrap/default.js

@@ -23,9 +23,18 @@
         return nativeLogError(e, args.map(arg => typeof arg === 'string' ? arg : prettyPrint(arg)).join(' '));
     }
 
+    // compare against the %TypedArray% intrinsic object all typed array constructors inherit from
+    function _isTypedArray(value) {
+        return value instanceof Object.getPrototypeOf(Uint8Array);
+    }
+
     function _hasStandardToString(value) {
         return value.toString === Object.prototype.toString ||
                 value.toString === Array.prototype.toString ||
+                // although TypedArrays have a standard Array.prototype.toString, we currently enforce an override to warn
+                // for legacy behaviour, making the toString non-standard for
+                // "any Uint8Array instances created in situations where previously a ByteArray would have been created"
+                _isTypedArray(value) ||
                 value.toString === Date.prototype.toString;
     }
 
@@ -64,7 +73,7 @@
 
     function formatObject(obj, printedObjects) {
         printedObjects.add(obj);
-        if (Array.isArray(obj))
+        if (Array.isArray(obj) || _isTypedArray(obj))
             return formatArray(obj, printedObjects).toString();
 
         if (obj instanceof Date)