lib/wasm: eliminate global namespace pollution in wasm_exec.js

Author: alexgleason

lib/wasm/wasm_exec.js

@@ -11,75 +11,71 @@
 return err;
 };
 
-if (!globalThis.fs) {
-let outputBuf = "";
-globalThis.fs = {
-constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1, O_DIRECTORY: -1 }, // unused
-writeSync(fd, buf) {
-outputBuf += decoder.decode(buf);
-const nl = outputBuf.lastIndexOf("\n");
-if (nl != -1) {
-console.log(outputBuf.substring(0, nl));
-outputBuf = outputBuf.substring(nl + 1);
-}
-return buf.length;
-},
-write(fd, buf, offset, length, position, callback) {
-if (offset !== 0 || length !== buf.length || position !== null) {
-callback(enosys());
-return;
-}
-const n = this.writeSync(fd, buf);
-callback(null, n);
-},
-chmod(path, mode, callback) { callback(enosys()); },
-chown(path, uid, gid, callback) { callback(enosys()); },
-close(fd, callback) { callback(enosys()); },
-fchmod(fd, mode, callback) { callback(enosys()); },
-fchown(fd, uid, gid, callback) { callback(enosys()); },
-fstat(fd, callback) { callback(enosys()); },
-fsync(fd, callback) { callback(null); },
-ftruncate(fd, length, callback) { callback(enosys()); },
-lchown(path, uid, gid, callback) { callback(enosys()); },
-link(path, link, callback) { callback(enosys()); },
-lstat(path, callback) { callback(enosys()); },
-mkdir(path, perm, callback) { callback(enosys()); },
-open(path, flags, mode, callback) { callback(enosys()); },
-read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
-readdir(path, callback) { callback(enosys()); },
-readlink(path, callback) { callback(enosys()); },
-rename(from, to, callback) { callback(enosys()); },
-rmdir(path, callback) { callback(enosys()); },
-stat(path, callback) { callback(enosys()); },
-symlink(path, link, callback) { callback(enosys()); },
-truncate(path, length, callback) { callback(enosys()); },
-unlink(path, callback) { callback(enosys()); },
-utimes(path, atime, mtime, callback) { callback(enosys()); },
-};
-}
+// Use local variables instead of polluting the global namespace.
+// These will be captured by closures in the importObject.
+let outputBuf = "";
+const fs = globalThis.fs || {
+constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1, O_DIRECTORY: -1 }, // unused
+writeSync(fd, buf) {
+outputBuf += decoder.decode(buf);
+const nl = outputBuf.lastIndexOf("\n");
+if (nl != -1) {
+console.log(outputBuf.substring(0, nl));
+outputBuf = outputBuf.substring(nl + 1);
+}
+return buf.length;
+},
+write(fd, buf, offset, length, position, callback) {
+if (offset !== 0 || length !== buf.length || position !== null) {
+callback(enosys());
+return;
+}
+const n = this.writeSync(fd, buf);
+callback(null, n);
+},
+chmod(path, mode, callback) { callback(enosys()); },
+chown(path, uid, gid, callback) { callback(enosys()); },
+close(fd, callback) { callback(enosys()); },
+fchmod(fd, mode, callback) { callback(enosys()); },
+fchown(fd, uid, gid, callback) { callback(enosys()); },
+fstat(fd, callback) { callback(enosys()); },
+fsync(fd, callback) { callback(null); },
+ftruncate(fd, length, callback) { callback(enosys()); },
+lchown(path, uid, gid, callback) { callback(enosys()); },
+link(path, link, callback) { callback(enosys()); },
+lstat(path, callback) { callback(enosys()); },
+mkdir(path, perm, callback) { callback(enosys()); },
+open(path, flags, mode, callback) { callback(enosys()); },
+read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
+readdir(path, callback) { callback(enosys()); },
+readlink(path, callback) { callback(enosys()); },
+rename(from, to, callback) { callback(enosys()); },
+rmdir(path, callback) { callback(enosys()); },
+stat(path, callback) { callback(enosys()); },
+symlink(path, link, callback) { callback(enosys()); },
+truncate(path, length, callback) { callback(enosys()); },
+unlink(path, callback) { callback(enosys()); },
+utimes(path, atime, mtime, callback) { callback(enosys()); },
+};
 
-if (!globalThis.process) {
-globalThis.process = {
-getuid() { return -1; },
-getgid() { return -1; },
-geteuid() { return -1; },
-getegid() { return -1; },
-getgroups() { throw enosys(); },
-pid: -1,
-ppid: -1,
-umask() { throw enosys(); },
-cwd() { throw enosys(); },
-chdir() { throw enosys(); },
-}
-}
+const process = globalThis.process || {
+getuid() { return -1; },
+getgid() { return -1; },
+geteuid() { return -1; },
+getegid() { return -1; },
+getgroups() { throw enosys(); },
+pid: -1,
+ppid: -1,
+umask() { throw enosys(); },
+cwd() { throw enosys(); },
+chdir() { throw enosys(); },
+};
 
-if (!globalThis.path) {
-globalThis.path = {
-resolve(...pathSegments) {
-return pathSegments.join("/");
-}
+const path = globalThis.path || {
+resolve(...pathSegments) {
+return pathSegments.join("/");
 }
-}
+};
 
 if (!globalThis.crypto) {
 throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)");
@@ -221,7 +217,7 @@
 return this._inst.exports.testExport(a, b);
 }
 
-const timeOrigin = Date.now() - performance.now();
+const timeOrigin = Date.now() - globalThis.performance.now();
 this.importObject = {
 _gotest: {
 add: (a, b) => a + b,
@@ -264,7 +260,7 @@
 // func nanotime1() int64
 "runtime.nanotime1": (sp) => {
 sp >>>= 0;
-setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
+setInt64(sp + 8, (timeOrigin + globalThis.performance.now()) * 1000000);
 },
 
 // func walltime() (sec int64, nsec int32)
@@ -306,7 +302,7 @@
 // func getRandomData(r []byte)
 "runtime.getRandomData": (sp) => {
 sp >>>= 0;
-crypto.getRandomValues(loadSlice(sp + 8));
+globalThis.crypto.getRandomValues(loadSlice(sp + 8));
 },
 
 // func finalizeRef(v ref)