Use Object.setPrototypeOf instead of Object.create+assign for bindings

Apparently some bundlers use objects with read-only properties for
imported modules. This conflicts with Object.assign even though the
object being assigned to only has read-only properties on its prototype.
Regardless, if the assignment is done before the prototype is set,
everything works just fine.

Fixes #2659

Author: CountBleck

src/bindings/js.ts

@@ -554,18 +554,10 @@ export class JSBuilder extends ExportsWalker {
         continue;
       }
       let resetPos = sb.length;
-      sb.push(": Object.assign(Object.create(");
-      if (moduleName == "env") {
-        sb.push("globalThis");
-      } else {
-        sb.push("__module");
-        sb.push(moduleId.toString());
-      }
-      sb.push("), ");
-      if (moduleName == "env") {
-        sb.push("imports.env || {}, ");
-      }
-      sb.push("{\n");
+
+      // Use Object.setPrototypeOf to avoid issues with read-only properties
+      // on module objects created by bundlers (issue #2659)
+      sb.push(": Object.setPrototypeOf({\n");
       ++this.indentLevel;
       let numInstrumented = 0;
       for (let _keys2 = Map_keys(module), j = 0, l = _keys2.length; j < l; ++j) {
@@ -598,7 +590,15 @@ export class JSBuilder extends ExportsWalker {
         sb.push(",\n");
       } else {
         indent(sb, this.indentLevel);
-        sb.push("}),\n");
+        sb.push("}, ");
+        if (moduleName == "env") {
+          // TODO: If necessary, use "Object.setPrototypeOf(Object.assign({}, imports.env || {}), globalThis)"
+          sb.push("Object.assign(Object.create(globalThis), imports.env || {})");
+        } else {
+          sb.push("__module");
+          sb.push(moduleId.toString());
+        }
+        sb.push("),\n");
       }
     }
     --this.indentLevel;

tests/compiler/bindings/esm.debug.js

@@ -1,6 +1,6 @@
 async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       trace(message, n, a0, a1, a2, a3, a4) {
         // ~lib/builtins/trace(~lib/string/String, i32?, f64?, f64?, f64?, f64?, f64?) => void
         message = __liftString(message >>> 0);
@@ -44,7 +44,7 @@ async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;

tests/compiler/bindings/esm.release.js

@@ -1,6 +1,6 @@
 async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       trace(message, n, a0, a1, a2, a3, a4) {
         // ~lib/builtins/trace(~lib/string/String, i32?, f64?, f64?, f64?, f64?, f64?) => void
         message = __liftString(message >>> 0);
@@ -44,7 +44,7 @@ async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;

tests/compiler/bindings/noExportRuntime.debug.js

@@ -1,6 +1,6 @@
 async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       abort(message, fileName, lineNumber, columnNumber) {
         // ~lib/builtins/abort(~lib/string/String | null?, ~lib/string/String | null?, u32?, u32?) => void
         message = __liftString(message >>> 0);
@@ -12,7 +12,7 @@ async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;

tests/compiler/bindings/noExportRuntime.release.js

@@ -1,6 +1,6 @@
 async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       abort(message, fileName, lineNumber, columnNumber) {
         // ~lib/builtins/abort(~lib/string/String | null?, ~lib/string/String | null?, u32?, u32?) => void
         message = __liftString(message >>> 0);
@@ -12,7 +12,7 @@ async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;

tests/compiler/bindings/raw.debug.js

@@ -1,6 +1,6 @@
 export async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       trace(message, n, a0, a1, a2, a3, a4) {
         // ~lib/builtins/trace(~lib/string/String, i32?, f64?, f64?, f64?, f64?, f64?) => void
         message = __liftString(message >>> 0);
@@ -44,7 +44,7 @@ export async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;

tests/compiler/bindings/raw.release.js

@@ -1,6 +1,6 @@
 export async function instantiate(module, imports = {}) {
   const adaptedImports = {
-    env: Object.assign(Object.create(globalThis), imports.env || {}, {
+    env: Object.setPrototypeOf({
       trace(message, n, a0, a1, a2, a3, a4) {
         // ~lib/builtins/trace(~lib/string/String, i32?, f64?, f64?, f64?, f64?, f64?) => void
         message = __liftString(message >>> 0);
@@ -44,7 +44,7 @@ export async function instantiate(module, imports = {}) {
           throw Error(`${message} in ${fileName}:${lineNumber}:${columnNumber}`);
         })();
       },
-    }),
+    }, Object.assign(Object.create(globalThis), imports.env || {})),
   };
   const { exports } = await WebAssembly.instantiate(module, adaptedImports);
   const memory = exports.memory || imports.env.memory;