1 files changed, 41 insertions, 0 deletions
diff --git a/ext/wasm/api/extern-post-js.js b/ext/wasm/api/extern-post-js.js
new file mode 100644
index 000000000..acb54c3c9
--- /dev/null
+++ b/ext/wasm/api/extern-post-js.js
@@ -0,0 +1,41 @@
+/* emscripten-js-addenda.js must be appended to the resulting sqlite3.js
+   file. */
+(function(){
+  /**
+     In order to hide the sqlite3InitModule()'s resulting Emscripten
+     module from downstream clients (and simplify our documentation by
+     being able to elide those details), we rewrite
+     sqlite3InitModule() to return the sqlite3 object.
+
+     Unfortunately, we cannot modify the module-loader/exporter-based
+     impls which Emscripten installs at some point in the file above
+     this.
+  */
+  const originalInit = self.sqlite3InitModule;
+  if(!originalInit){
+    throw new Error("Expecting self.sqlite3InitModule to be defined by the Emscripten build.");
+  }
+  self.sqlite3InitModule.ready = originalInit.ready;
+  self.sqlite3InitModule = (...args)=>{
+    //console.warn("Using replaced sqlite3InitModule()",self.location);
+    return originalInit(...args).then((EmscriptenModule)=>{
+      if(self.window!==self &&
+         (EmscriptenModule['ENVIRONMENT_IS_PTHREAD']
+          || EmscriptenModule['_pthread_self']
+          || 'function'===typeof threadAlert
+          || self.location.pathname.endsWith('.worker.js')
+         )){
+        /** Workaround for wasmfs-generated worker, which calls this
+            routine from each individual thread and requires that its
+            argument be returned. All of the criteria above are fragile,
+            based solely on inspection of the offending code, not public
+            Emscripten details. */
+        return EmscriptenModule;
+      }
+      const f = EmscriptenModule.sqlite3.asyncPostInit;
+      delete EmscriptenModule.sqlite3.asyncPostInit;
+      return f();
+    });
+  };
+  //console.warn("Replaced sqlite3InitModule()");
+})();