diff --git a/ext/wasm/api/sqlite3-api-oo1.js b/ext/wasm/api/sqlite3-api-oo1.js
index e318b72001..aaaeaa3d5a 100644
--- a/ext/wasm/api/sqlite3-api-oo1.js
+++ b/ext/wasm/api/sqlite3-api-oo1.js
@@ -258,9 +258,9 @@ self.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
      in the form of a single configuration object with the following
      properties:
 
-     - `.filename`: database file name
-     - `.flags`: open-mode flags
-     - `.vfs`: the VFS fname
+     - `filename`: database file name
+     - `flags`: open-mode flags
+     - `vfs`: the VFS fname
 
      The `filename` and `vfs` arguments may be either JS strings or
      C-strings allocated via WASM. `flags` is required to be a JS
@@ -560,6 +560,25 @@ self.sqlite3ApiBootstrap.initializers.push(function(sqlite3){
     dbName: function(dbNumber=0){
       return capi.sqlite3_db_name(affirmDbOpen(this).pointer, dbNumber);
     },
+    /**
+       Returns the name of the sqlite3_vfs used by the given database
+       of this connection (defaulting to 'main'). The argument may be
+       either a JS string or a WASM C-string. Returns undefined if the
+       given db name is invalid. Throws if this object has been
+       close()d.
+    */
+    dbVfsName: function(dbName=0){
+      let rc;
+      const pVfs = capi.sqlite3_js_db_vfs(
+        affirmDbOpen(this).pointer, dbName
+      );
+      if(pVfs){
+        const v = new capi.sqlite3_vfs(pVfs);
+        try{ rc = wasm.cstringToJs(v.$zName) }
+        finally { v.dispose() }
+      }
+      return rc;        
+    },
     /**
        Compiles the given SQL and returns a prepared Stmt. This is
        the only way to create new Stmt objects. Throws on error.
diff --git a/ext/wasm/api/sqlite3-api-opfs.js b/ext/wasm/api/sqlite3-api-opfs.js
index 1a89432c5f..90337d5279 100644
--- a/ext/wasm/api/sqlite3-api-opfs.js
+++ b/ext/wasm/api/sqlite3-api-opfs.js
@@ -371,6 +371,20 @@ const installOpfsVfs = function callee(options){
       return rc;
     };
 
+    /**
+       Not part of the public API. Only for test/development use.
+    */
+    opfsUtil.debug = {
+      asyncShutdown: ()=>{
+        warn("Shutting down OPFS async listener. The OPFS VFS will no longer work.");
+        opRun('opfs-async-shutdown');
+      },
+      asyncRestart: ()=>{
+        warn("Attempting to restart OPFS VFS async listener. Might work, might not.");
+        W.postMessage({type: 'opfs-async-restart'});
+      }
+    };
+
     const initS11n = ()=>{
       /**
          !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
@@ -876,37 +890,61 @@ const installOpfsVfs = function callee(options){
     }
 
     /**
-       Syncronously deletes the given OPFS filesystem entry, ignoring
-       any errors. As this environment has no notion of "current
-       directory", the given name must be an absolute path. If the 2nd
-       argument is truthy, deletion is recursive (use with caution!).
-
-       Returns true if the deletion succeeded and false if it fails,
-       but cannot report the nature of the failure.
+       Expects an OPFS file path. It gets resolved, such that ".."
+       components are properly expanded, and returned. If the 2nd arg
+       is true, the result is returned as an array of path elements,
+       else an absolute path string is returned.
     */
-    opfsUtil.deleteEntry = function(fsEntryName,recursive=false){
-      mTimeStart('xDelete');
-      const rc = opRun('xDelete', fsEntryName, 0, recursive);
-      mTimeEnd();
-      return 0===rc;
+    opfsUtil.getResolvedPath = function(filename,splitIt){
+      const p = new URL(filename, "file://irrelevant").pathname;
+      return splitIt ? p.split('/').filter((v)=>!!v) : p;
     };
+
     /**
-       Synchronously creates the given directory name, recursively, in
+       Takes the absolute path to a filesystem element. Returns an
+       array of [handleOfContainingDir, filename]. If the 2nd argument
+       is truthy then each directory element leading to the file is
+       created along the way. Throws if any creation or resolution
+       fails.
+    */
+    opfsUtil.getDirForFilename = async function f(absFilename, createDirs = false){
+      const path = opfsUtil.getResolvedPath(absFilename, true);
+      const filename = path.pop();
+      let dh = opfsUtil.rootDirectory;
+      for(const dirName of path){
+        if(dirName){
+          dh = await dh.getDirectoryHandle(dirName, {create: !!createDirs});
+        }
+      }
+      return [dh, filename];
+    };
+
+    /**
+       Creates the given directory name, recursively, in
        the OPFS filesystem. Returns true if it succeeds or the
        directory already exists, else false.
     */
-    opfsUtil.mkdir = function(absDirName){
-      mTimeStart('mkdir');
-      const rc = opRun('mkdir', absDirName);
-      mTimeEnd();
-      return 0===rc;
+    opfsUtil.mkdir = async function(absDirName){
+      try {
+        await opfsUtil.getDirForFilename(absDirName+"/filepart", true);
+        return true;
+      }catch(e){
+        //console.warn("mkdir(",absDirName,") failed:",e);
+        return false;
+      }
     };
     /**
-       Synchronously checks whether the given OPFS filesystem exists,
+       Checks whether the given OPFS filesystem entry exists,
        returning true if it does, false if it doesn't.
     */
-    opfsUtil.entryExists = function(fsEntryName){
-      return 0===opRun('xAccess', fsEntryName);
+    opfsUtil.entryExists = async function(fsEntryName){
+      try {
+        const [dh, fn] = await opfsUtil.getDirForFilename(filename);
+        await dh.getFileHandle(fn);
+        return true;
+      }catch(e){
+        return false;
+      }
     };
 
     /**
@@ -938,20 +976,160 @@ const installOpfsVfs = function callee(options){
     };
 
     /**
-       Only for test/development use.
+       Returns a promise which resolves to an object which represents
+       all files and directories in the OPFS tree. The top-most object
+       has two properties: `dirs` is an array of directory entries
+       (described below) and `files` is a list of file names for all
+       files in that directory.
+
+       Traversal starts at sqlite3.opfs.rootDirectory.
+
+       Each `dirs` entry is an object in this form:
+
+       ```
+       { name: directoryName,
+         dirs: [...subdirs],
+         files: [...file names]
+       }
+       ```
+
+       The `files` and `subdirs` entries are always set but may be
+       empty arrays.
+
+       The returned object has the same structure but its `name` is
+       an empty string. All returned objects are created with
+       Object.create(null), so have no prototype.
+
+       Design note: the entries do not contain more information,
+       e.g. file sizes, because getting such info is not only
+       expensive but is subject to locking-related errors.
     */
-    opfsUtil.debug = {
-      asyncShutdown: ()=>{
-        warn("Shutting down OPFS async listener. OPFS will no longer work.");
-        opRun('opfs-async-shutdown');
-      },
-      asyncRestart: ()=>{
-        warn("Attempting to restart OPFS async listener. Might work, might not.");
-        W.postMessage({type: 'opfs-async-restart'});
+    opfsUtil.treeList = async function(){
+      const doDir = async function callee(dirHandle,tgt){
+        tgt.name = dirHandle.name;
+        tgt.dirs = [];
+        tgt.files = [];
+        for await (const handle of dirHandle.values()){
+          if('directory' === handle.kind){
+            const subDir = Object.create(null);
+            tgt.dirs.push(subDir);
+            await callee(handle, subDir);
+          }else{
+            tgt.files.push(handle.name);
+          }
+        }
+      };
+      const root = Object.create(null);
+      await doDir(opfsUtil.rootDirectory, root);
+      return root;
+    };
+
+    /**
+       Irrevocably deletes _all_ files in the current origin's OPFS.
+       Obviously, this must be used with great caution. It may throw
+       an exception if removal of anything fails (e.g. a file is
+       locked), but the precise conditions under which it will throw
+       are not documented (so we cannot tell you what they are).
+    */
+    opfsUtil.rmfr = async function(){
+      const dir = opfsUtil.rootDirectory, opt = {recurse: true};
+      for await (const handle of dir.values()){
+        dir.removeEntry(handle.name, opt);
       }
     };
 
-    //TODO to support fiddle db upload:
+    /**
+       Deletes the given OPFS filesystem entry.  As this environment
+       has no notion of "current directory", the given name must be an
+       absolute path. If the 2nd argument is truthy, deletion is
+       recursive (use with caution!).
+
+       The returned Promise resolves to true if the deletion was
+       successful, else false (but...). The OPFS API reports the
+       reason for the failure only in human-readable form, not
+       exceptions which can be type-checked to determine the
+       failure. Because of that...
+
+       If the final argument is truthy then this function will
+       propagate any exception on error, rather than returning false.
+    */
+    opfsUtil.unlink = async function(fsEntryName, recursive = false,
+                                          throwOnError = false){
+      try {
+        const [hDir, filenamePart] =
+              await opfsUtil.getDirForFilename(fsEntryName, false);
+        await hDir.removeEntry(filenamePart, {recursive});
+        return true;
+      }catch(e){
+        if(throwOnError){
+          throw new Error("unlink(",arguments[0],") failed: "+e.message,{
+            cause: e
+          });
+        }
+        return false;
+      }
+    };
+
+    /**
+       Traverses the OPFS filesystem, calling a callback for each one.
+       The argument may be either a callback function or an options object
+       with any of the following properties:
+
+       - `callback`: function which gets called for each filesystem
+         entry.  It gets passed 3 arguments: 1) the
+         FileSystemFileHandle or FileSystemDirectoryHandle of each
+         entry (noting that both are instanceof FileSystemHandle). 2)
+         the FileSystemDirectoryHandle of the parent directory. 3) the
+         current depth level, with 0 being at the top of the tree
+         relative to the starting directory. If the callback returns a
+         literal false, as opposed to any other falsy value, traversal
+         stops without an error. Any exceptions it throws are
+         propagated. Results are undefined if the callback manipulate
+         the filesystem (e.g. removing or adding entries) because the
+         how OPFS iterators behave in the face of such changes is
+         undocumented.
+
+       - `recursive` [bool=true]: specifies whether to recurse into
+         subdirectories or not. Whether recursion is depth-first or
+         breadth-first is unspecified!
+
+       - `directory` [FileSystemDirectoryEntry=sqlite3.opfs.rootDirectory]
+         specifies the starting directory.
+
+       If this function is passed a function, it is assumed to be the
+       callback.
+
+       Returns a promise because it has to (by virtue of being async)
+       but that promise has no specific meaning: the traversal it
+       performs is synchronous. The promise must be used to catch any
+       exceptions propagated by the callback, however.
+
+       TODO: add an option which specifies whether to traverse
+       depth-first or breadth-first. We currently do depth-first but
+       an incremental file browsing widget would benefit more from
+       breadth-first.
+    */
+    opfsUtil.traverse = async function(opt){
+      const defaultOpt = {
+        recursive: true,
+        directory: opfsUtil.rootDirectory
+      };
+      if('function'===typeof opt){
+        opt = {callback:opt};
+      }
+      opt = Object.assign(defaultOpt, opt||{});
+      const doDir = async function callee(dirHandle, depth){
+        for await (const handle of dirHandle.values()){
+          if(false === opt.callback(handle, dirHandle, depth)) return false;
+          else if(opt.recursive && 'directory' === handle.kind){
+            if(false === await callee(handle, depth + 1)) break;
+          }
+        }
+      };
+      doDir(opt.directory, 0);
+    };
+
+    //TODO to support fiddle and worker1 db upload:
     //opfsUtil.createFile = function(absName, content=undefined){...}
 
     if(sqlite3.oo1){
diff --git a/ext/wasm/api/sqlite3-api-prologue.js b/ext/wasm/api/sqlite3-api-prologue.js
index a5ff0c40ad..ca6fad8f84 100644
--- a/ext/wasm/api/sqlite3-api-prologue.js
+++ b/ext/wasm/api/sqlite3-api-prologue.js
@@ -1187,14 +1187,15 @@ self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
   }
 
   /**
-     Given an `sqlite3*`, an sqlite3_vfs name, and an optional db
-     name, returns a truthy value (see below) if that db handle uses
-     that VFS, else returns false. If pDb is falsy then the 3rd
-     argument is ignored and this function returns a truthy value if
-     the default VFS name matches that of the 2nd argument. Results
-     are undefined if pDb is truthy but refers to an invalid
-     pointer. The 3rd argument specifies the database name of the
-     given database connection to check, defaulting to the main db.
+     Given an `sqlite3*`, an sqlite3_vfs name, and an optional db name
+     (defaulting to "main"), returns a truthy value (see below) if
+     that db uses that VFS, else returns false. If pDb is falsy then
+     the 3rd argument is ignored and this function returns a truthy
+     value if the default VFS name matches that of the 2nd
+     argument. Results are undefined if pDb is truthy but refers to an
+     invalid pointer. The 3rd argument specifies the database name of
+     the given database connection to check, defaulting to the main
+     db.
 
      The 2nd and 3rd arguments may either be a JS string or a WASM
      C-string. If the 2nd argument is a NULL WASM pointer, the default
@@ -1209,14 +1210,14 @@ self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
      bad arguments cause a conversion error when passing into
      wasm-space, false is returned.
   */
-  capi.sqlite3_js_db_uses_vfs = function(pDb,vfsName,dbName="main"){
+  capi.sqlite3_js_db_uses_vfs = function(pDb,vfsName,dbName=0){
     try{
       const pK = capi.sqlite3_vfs_find(vfsName);
       if(!pK) return false;
       else if(!pDb){
         return pK===capi.sqlite3_vfs_find(0) ? pK : false;
       }else{
-        return pK===capi.sqlite3_js_db_vfs(pDb) ? pK : false;
+        return pK===capi.sqlite3_js_db_vfs(pDb,dbName) ? pK : false;
       }
     }catch(e){
       /* Ignore - probably bad args to a wasm-bound function. */
diff --git a/ext/wasm/api/sqlite3-api-worker1.js b/ext/wasm/api/sqlite3-api-worker1.js
index aa438a52dc..532d61b67e 100644
--- a/ext/wasm/api/sqlite3-api-worker1.js
+++ b/ext/wasm/api/sqlite3-api-worker1.js
@@ -188,6 +188,8 @@
       See the sqlite3.oo1.DB constructor for peculiarities and
       transformations,
 
+      vfs: sqlite3_vfs name. Ignored if filename is ":memory:" or "".
+           This may change how the given filename is resolved.
     }
   }
   ```
@@ -212,6 +214,7 @@
       persistent: true if the given filename resides in the
       known-persistent storage, else false.
 
+      vfs: name of the VFS the "main" db is using.
    }
   }
   ```
@@ -362,7 +365,7 @@ sqlite3.initWorker1API = function(){
     /** Temp holder for "transferable" postMessage() state. */
     xfer: [],
     open: function(opt){
-      const db = new DB(opt.filename);
+      const db = new DB(opt);
       this.dbs[getDbId(db)] = db;
       if(this.dbList.indexOf(db)<0) this.dbList.push(db);
       return db;
@@ -442,12 +445,14 @@ sqlite3.initWorker1API = function(){
         oargs.filename = args.filename || '';
       }else{
         oargs.filename = args.filename;
+        oargs.vfs = args.vfs;
       }
       const db = wState.open(oargs);
       rc.filename = db.filename;
       rc.persistent = (!!pDir && db.filename.startsWith(pDir+'/'))
         || !!sqlite3.capi.sqlite3_js_db_uses_vfs(db.pointer, "opfs");
       rc.dbId = getDbId(db);
+      rc.vfs = db.dbVfsName();
       return rc;
     },
 
@@ -528,6 +533,7 @@ sqlite3.initWorker1API = function(){
       rc.wasmfsOpfsEnabled = !!sqlite3.capi.sqlite3_wasmfs_opfs_dir();
       rc.version = sqlite3.version;
       rc.vfsList = sqlite3.capi.sqlite3_js_vfs_list();
+      rc.opfsEnabled = !!sqlite3.opfs;
       return rc;
     },
 
@@ -542,11 +548,6 @@ sqlite3.initWorker1API = function(){
        }
     */
     export: function(ev){
-      /**
-         We need to reimplement this to use the Emscripten FS
-         interface. That part used to be in the OO#1 API but that
-         dependency was removed from that level of the API.
-      */
       const db = getMsgDb(ev);
       const response = {
         bytearray: sqlite3.capi.sqlite3_js_db_export(db.pointer),
@@ -559,17 +560,23 @@ sqlite3.initWorker1API = function(){
 
     toss: function(ev){
       toss("Testing worker exception");
+    },
+
+    'opfs-tree': async function(ev){
+      if(!sqlite3.opfs) toss("OPFS support is unavailable.");
+      const response = await sqlite3.opfs.treeList();
+      return response;
     }
   }/*wMsgHandler*/;
 
-  self.onmessage = function(ev){
+  self.onmessage = async function(ev){
     ev = ev.data;
     let result, dbId = ev.dbId, evType = ev.type;
     const arrivalTime = performance.now();
     try {
       if(wMsgHandler.hasOwnProperty(evType) &&
          wMsgHandler[evType] instanceof Function){
-        result = wMsgHandler[evType](ev);
+        result = await wMsgHandler[evType](ev);
       }else{
         toss("Unknown db worker message type:",ev.type);
       }
diff --git a/ext/wasm/api/sqlite3-opfs-async-proxy.js b/ext/wasm/api/sqlite3-opfs-async-proxy.js
index 71c822c1f2..3aa20fa634 100644
--- a/ext/wasm/api/sqlite3-opfs-async-proxy.js
+++ b/ext/wasm/api/sqlite3-opfs-async-proxy.js
@@ -377,6 +377,7 @@ const vfsAsyncImpls = {
         if(!filenamePart) break;
         await hDir.removeEntry(filenamePart, {recursive});
         if(0x1234 !== syncDir) break;
+        recursive = false;
         filename = getResolvedPath(filename, true);
         filename.pop();
         filename = filename.join('/');
diff --git a/ext/wasm/common/testing.css b/ext/wasm/common/testing.css
index a4433af8c6..9438b330c9 100644
--- a/ext/wasm/common/testing.css
+++ b/ext/wasm/common/testing.css
@@ -37,6 +37,8 @@ span.labeled-input {
 .strong { font-weight: 700 }
 .warning { color: firebrick; }
 .green { color: darkgreen; }
+.tests-pass { background-color: green; color: white }
+.tests-fail { background-color: red; color: yellow }
 .faded { opacity: 0.5; }
 .group-start { color: blue; }
 .group-end { color: blue; }
diff --git a/ext/wasm/demo-worker1-promiser.js b/ext/wasm/demo-worker1-promiser.js
index 855643b2d2..3f50ef9e08 100644
--- a/ext/wasm/demo-worker1-promiser.js
+++ b/ext/wasm/demo-worker1-promiser.js
@@ -91,7 +91,8 @@
       const r = ev.result;
       log("then open result",r);
       T.assert(ev.dbId === r.dbId)
-        .assert(ev.messageId);
+        .assert(ev.messageId)
+        .assert('string' === typeof r.vfs);
       promiserConfig.dbId = ev.dbId;
     }).then(runTests2);
   };
diff --git a/ext/wasm/demo-worker1.js b/ext/wasm/demo-worker1.js
index 2da80bc239..ac4e9f4234 100644
--- a/ext/wasm/demo-worker1.js
+++ b/ext/wasm/demo-worker1.js
@@ -291,7 +291,8 @@
       log("open result",ev);
       T.assert('testing2.sqlite3'===ev.result.filename)
         .assert(ev.dbId)
-        .assert(ev.messageId);
+        .assert(ev.messageId)
+        .assert('string' === typeof ev.result.vfs);
       DbState.id = ev.dbId;
       if(waitForOpen) setTimeout(runTests2, 0);
     });
diff --git a/ext/wasm/test-opfs-vfs.js b/ext/wasm/test-opfs-vfs.js
index e22acc0e3d..bba31bb9c9 100644
--- a/ext/wasm/test-opfs-vfs.js
+++ b/ext/wasm/test-opfs-vfs.js
@@ -37,7 +37,7 @@ const tryOpfsVfs = async function(sqlite3){
 
   const urlArgs = new URL(self.location.href).searchParams;
   const dbFile = "my-persistent.db";
-  if(urlArgs.has('delete')) sqlite3.opfs.deleteEntry(dbFile);
+  if(urlArgs.has('delete')) sqlite3.opfs.unlink(dbFile);
 
   const db = new opfs.OpfsDb(dbFile,'ct');
   log("db file:",db.filename);
@@ -62,13 +62,14 @@ const tryOpfsVfs = async function(sqlite3){
     // Some sanity checks of the opfs utility functions...
     const testDir = '/sqlite3-opfs-'+opfs.randomFilename(12);
     const aDir = testDir+'/test/dir';
-    opfs.mkdir(aDir) || toss("mkdir failed");
-    opfs.mkdir(aDir) || toss("mkdir must pass if the dir exists");
-    opfs.deleteEntry(testDir+'/test') && toss("delete 1 should have failed (dir not empty)");
-    opfs.deleteEntry(testDir+'/test/dir') || toss("delete 2 failed");
-    opfs.deleteEntry(testDir+'/test/dir') && toss("delete 2b should have failed (dir already deleted)");
-    opfs.deleteEntry(testDir,true) || toss("delete 3 failed");
-    opfs.entryExists(testDir) && toss("entryExists(",testDir,") should have failed");
+    await opfs.mkdir(aDir) || toss("mkdir failed");
+    await opfs.mkdir(aDir) || toss("mkdir must pass if the dir exists");
+    await opfs.unlink(testDir+'/test') && toss("delete 1 should have failed (dir not empty)");
+    //await opfs.entryExists(testDir)
+    await opfs.unlink(testDir+'/test/dir') || toss("delete 2 failed");
+    await opfs.unlink(testDir+'/test/dir') && toss("delete 2b should have failed (dir already deleted)");
+    await opfs.unlink(testDir, true) || toss("delete 3 failed");
+    await opfs.entryExists(testDir) && toss("entryExists(",testDir,") should have failed");
   }finally{
     db.close();
   }
diff --git a/ext/wasm/tester1-worker.html b/ext/wasm/tester1-worker.html
index e1a7247e3e..4d2df0c8d1 100644
--- a/ext/wasm/tester1-worker.html
+++ b/ext/wasm/tester1-worker.html
@@ -14,7 +14,7 @@
     </style>
   </head>
   <body>
-    <h1>sqlite3 WASM/JS tester #1 (Worker thread)</h1>
+    <h1 id='color-target'>sqlite3 WASM/JS tester #1 (Worker thread)</h1>
     <div>See <a href='tester1.html' target='tester1.html'>tester1.html</a>
       for the UI-thread variant.</div>
     <div class='input-wrapper'>
@@ -46,6 +46,14 @@
             case 'log':
               logHtml(data.payload.cssClass, ...data.payload.args);
               break;
+            case 'error':
+              logHtml('error', ...data.payload.args);
+              break;
+            case 'test-result':
+              document.querySelector('#color-target').classList.add(
+                data.payload.pass ? 'tests-pass' : 'tests-fail'
+              );
+              break;
             default:
               logHtml('error',"Unhandled message:",data.type);
         };
diff --git a/ext/wasm/tester1.html b/ext/wasm/tester1.html
index 0ceacc5c36..f7a2fba4af 100644
--- a/ext/wasm/tester1.html
+++ b/ext/wasm/tester1.html
@@ -14,7 +14,7 @@
     </style>
   </head>
   <body>
-    <h1>sqlite3 WASM/JS tester #1 (UI thread)</h1>
+    <h1 id='color-target'>sqlite3 WASM/JS tester #1 (UI thread)</h1>
     <div>See <a href='tester1-worker.html' target='tester1-worker.html'>tester1-worker.html</a>
       for the Worker-thread variant.</div>
     <div class='input-wrapper'>
diff --git a/ext/wasm/tester1.js b/ext/wasm/tester1.js
index 016886a30a..4f32368701 100644
--- a/ext/wasm/tester1.js
+++ b/ext/wasm/tester1.js
@@ -99,6 +99,14 @@
       };
     }
   }
+  const reportFinalTestStatus = function(pass){
+    if(isUIThread()){
+      const e = document.querySelector('#color-target');
+      e.classList.add(pass ? 'tests-pass' : 'tests-fail');
+    }else{
+      postMessage({type:'test-result', payload:{pass}});
+    }
+  };
   const log = (...args)=>{
     //console.log(...args);
     logClass('',...args);
@@ -139,28 +147,19 @@
     toBool: function(expr){
       return (expr instanceof Function) ? !!expr() : !!expr;
     },
-    /** abort() if expr is false. If expr is a function, it
-        is called and its result is evaluated.
+    /** Throws if expr is false. If expr is a function, it is called
+        and its result is evaluated. If passed multiple arguments,
+        those after the first are a message string which get applied
+        as an exception message if the assertion fails. The message
+        arguments are concatenated together with a space between each.
     */
-    assert: function f(expr, msg){
-      if(!f._){
-        f._ = ('undefined'===typeof abort
-               ? (msg)=>{throw new Error(msg)}
-               : abort);
-      }
+    assert: function f(expr, ...msg){
       ++this.counter;
       if(!this.toBool(expr)){
-        f._(msg || "Assertion failed.");
+        throw new Error(msg.length ? msg.join(' ') : "Assertion failed.");
       }
       return this;
     },
-    /** Identical to assert() but throws instead of calling
-        abort(). */
-    affirm: function(expr, msg){
-      ++this.counter;
-      if(!this.toBool(expr)) throw new Error(msg || "Affirmation failed.");
-      return this;
-    },
     /** Calls f() and squelches any exception it throws. If it
         does not throw, this function throws. */
     mustThrow: function(f, msg){
@@ -301,9 +300,11 @@
                    "Done running tests.",TestUtil.counter,"assertions in",
                    roundMs(runtime),'ms');
           pok();
+          reportFinalTestStatus(true);
         }catch(e){
           error(e);
           pnok(e);
+          reportFinalTestStatus(false);
         }
       }.bind(this));
     }
@@ -1117,10 +1118,11 @@
       const dbFile = '/tester1.db';
       wasm.sqlite3_wasm_vfs_unlink(0, dbFile);
       const db = this.db = new sqlite3.oo1.DB(dbFile);
-      T.assert(Number.isInteger(db.pointer)).
-        mustThrowMatching(()=>db.pointer=1, /read-only/).
-        assert(0===sqlite3.capi.sqlite3_extended_result_codes(db.pointer,1)).
-        assert('main'===db.dbName(0));
+      T.assert(Number.isInteger(db.pointer))
+        .mustThrowMatching(()=>db.pointer=1, /read-only/)
+        .assert(0===sqlite3.capi.sqlite3_extended_result_codes(db.pointer,1))
+        .assert('main'===db.dbName(0))
+        .assert('string' === typeof db.dbVfsName());
       // Custom db error message handling via sqlite3_prepare_v2/v3()
       let rc = capi.sqlite3_prepare_v3(db.pointer, {/*invalid*/}, -1, 0, null, null);
       T.assert(capi.SQLITE_MISUSE === rc)
@@ -1737,13 +1739,14 @@
       (sqlite3)=>{return !!sqlite3.opfs})
     .t({
       name: 'OPFS sanity checks',
-      test: function(sqlite3){
+      test: async function(sqlite3){
+        const opfs = sqlite3.opfs;
         const filename = 'sqlite3-tester1.db';
         const pVfs = capi.sqlite3_vfs_find('opfs');
         T.assert(pVfs);
         const unlink = (fn=filename)=>wasm.sqlite3_wasm_vfs_unlink(pVfs,fn);
         unlink();
-        let db = new sqlite3.opfs.OpfsDb(filename);
+        let db = new opfs.OpfsDb(filename);
         try {
           db.exec([
             'create table p(a);',
@@ -1751,13 +1754,26 @@
           ]);
           T.assert(3 === db.selectValue('select count(*) from p'));
           db.close();
-          db = new sqlite3.opfs.OpfsDb(filename);
+          db = new opfs.OpfsDb(filename);
           db.exec('insert into p(a) values(4),(5),(6)');
           T.assert(6 === db.selectValue('select count(*) from p'));
         }finally{
           db.close();
           unlink();
         }
+
+        // Some sanity checks of the opfs utility functions...
+        const testDir = '/sqlite3-opfs-'+opfs.randomFilename(12);
+        const aDir = testDir+'/test/dir';
+        T.assert(await opfs.mkdir(aDir), "mkdir failed")
+          .assert(await opfs.mkdir(aDir), "mkdir must pass if the dir exists")
+          .assert(!(await opfs.unlink(testDir+'/test')), "delete 1 should have failed (dir not empty)")
+          .assert((await opfs.unlink(testDir+'/test/dir')), "delete 2 failed")
+          .assert(!(await opfs.unlink(testDir+'/test/dir')),
+                  "delete 2b should have failed (dir already deleted)")
+          .assert((await opfs.unlink(testDir, true)), "delete 3 failed")
+          .assert(!(await opfs.entryExists(testDir)),
+                  "entryExists(",testDir,") should have failed");
       }
     }/*OPFS sanity checks*/)
   ;/* end OPFS tests */
diff --git a/manifest b/manifest
index 2d888a58ab..f644d6bc06 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Make\sthe\sUPDATE\smethod\sof\sthe\ssqlite_dbpage\svirtual\stable\srebust\sagainst\nOOM\serrors.\s\s[forum:/forumpost/bbcf0dd6ca|Forum\spost\sbbcf0dd6ca].\s\sTest\scase\nin\sTH3.
-D 2022-10-31T18:01:05.280
+C Significant\scleanups\sand\sexpansion\sof\sthe\ssqlite3.opfs\sutilities.\sAdd\soo1.DB.dbVfsName().\sAdd\sVFS\sname\sto\sworker1:open's\sarguments\sand\sresult.
+D 2022-11-01T07:49:49.018
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -500,12 +500,12 @@ F ext/wasm/api/post-js-header.js d6ab3dfef4a06960d28a7eaa338d4e2a1a5981e9b387181
 F ext/wasm/api/pre-js.js 287e462f969342b032c03900e668099fa1471d852df7a472de5bc349161d9c04
 F ext/wasm/api/sqlite3-api-cleanup.js ecdc69dbfccfe26146f04799fcfd4a6f5790d46e7e3b9b6e9b0491f92ed8ae34
 F ext/wasm/api/sqlite3-api-glue.js ebfd1d01b249c705482bfe3bdef3b1feaecf55821c46abf79b8105ec9b1c2b1a
-F ext/wasm/api/sqlite3-api-oo1.js 4028bc2bac7e3ae2d23b7c99828155b4a06da006b51dc2a929bc0db26337370d
-F ext/wasm/api/sqlite3-api-opfs.js 6880cc79a4d1b6075942298d9d1ab07e24d81fbd9e5fe6b7c797b86e4b2af596
-F ext/wasm/api/sqlite3-api-prologue.js 873986ca150c79510f647b910f8349bc71b14db21e444cab3b9fad9c4f39ffc7
-F ext/wasm/api/sqlite3-api-worker1.js 7de5160ba86ed216e8b99ba1ae0c39c1ff85c11a4818252bfc8dd0dc21109b84
+F ext/wasm/api/sqlite3-api-oo1.js ce8db98ab7c394fd8fb99ae135c46269a1a0162250a70e39e7975b4317a03640
+F ext/wasm/api/sqlite3-api-opfs.js 59b278ed00764fc47ba88be0582ab3fc3ce725e02b6d86459464cc029b9ac356
+F ext/wasm/api/sqlite3-api-prologue.js 850581aa0c759db25c04d64b340b0c5272f253fb195377acc8d851e376710ad3
+F ext/wasm/api/sqlite3-api-worker1.js 4f920a54fb97d4ca50632d45bd7d011a55016eb5a5883725033abb450903bc6f
 F ext/wasm/api/sqlite3-license-version-header.js a661182fc93fc2cf212dfd0b987f8e138a3ac98f850b1112e29b5fbdaecc87c3
-F ext/wasm/api/sqlite3-opfs-async-proxy.js b2264efef84c4a0af5dab426d7573d8b4ee5af3a25ba108b709a835a613c5e36
+F ext/wasm/api/sqlite3-opfs-async-proxy.js 2627bf8dc04c24783a55de40d8a6d18da31e81a9bb926a5b672b402f582099b5
 F ext/wasm/api/sqlite3-wasi.h 25356084cfe0d40458a902afb465df8c21fc4152c1d0a59b563a3fba59a068f9
 F ext/wasm/api/sqlite3-wasm.c 14ac9c03f6585332f882703f3427f11ffe8ffe8b6c0e252be2c518f7aac6ab6a
 F ext/wasm/api/sqlite3-worker1-promiser.js 0c7a9826dbf82a5ed4e4f7bf7816e825a52aff253afbf3350431f5773faf0e4b
@@ -514,7 +514,7 @@ F ext/wasm/batch-runner.html 4deeed44fe41496dc6898d9fb17938ea3291f40f4bfb977e29d
 F ext/wasm/batch-runner.js 49609e89aaac9989d6c1ad3fae268e4878e1ad7bc5fd3e5c2f44959660780b2e
 F ext/wasm/common/SqliteTestUtil.js d8bf97ecb0705a2299765c8fc9e11b1a5ac7f10988bbf375a6558b7ca287067b
 F ext/wasm/common/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
-F ext/wasm/common/testing.css 739b58c44511f642f16f57b701c84dc9ee412d8bc47b3d8a99d947babfa69d9d
+F ext/wasm/common/testing.css 35889709547d89a6109ff83b25c11bbc91d8dd43aab8722e428655ca98880a06
 F ext/wasm/common/whwasmutil.js 77930367c2a65cf6fd6f99ad3644ede33e4d20466f5e506eb87b8d101a0a7655
 F ext/wasm/demo-123-worker.html a0b58d9caef098a626a1a1db567076fca4245e8d60ba94557ede8684350a81ed
 F ext/wasm/demo-123.html 8c70a412ce386bd3796534257935eb1e3ea5c581e5d5aea0490b8232e570a508
@@ -522,9 +522,9 @@ F ext/wasm/demo-123.js ebae30756585bca655b4ab2553ec9236a87c23ad24fc8652115dcedb0
 F ext/wasm/demo-jsstorage.html 409c4be4af5f207fb2877160724b91b33ea36a3cd8c204e8da1acb828ffe588e
 F ext/wasm/demo-jsstorage.js 44e3ae7ec2483b6c511384c3c290beb6f305c721186bcf5398ca4e00004a06b8
 F ext/wasm/demo-worker1-promiser.html 1de7c248c7c2cfd4a5783d2aa154bce62d74c6de98ab22f5786620b3354ed15f
-F ext/wasm/demo-worker1-promiser.js f68ffbbe1c6086e18ce7961b8fc2b40dd88db174f59052e228c06b07484945ca
+F ext/wasm/demo-worker1-promiser.js 988ce92220c1cf1dd95fcb6b59734f0ae677942469390ddd8a64f4bbb5f99821
 F ext/wasm/demo-worker1.html 2c178c1890a2beb5a5fecb1453e796d067a4b8d3d2a04d65ca2eb1ab2c68ef5d
-F ext/wasm/demo-worker1.js 8ba51d94c4601fa5c313d9e59b63b238f5305b5d5739ad21f4782a0161e6682e
+F ext/wasm/demo-worker1.js 117e4eedc62e103e287f0e4a694add7e13a200a4d7056e718645032288c4a8ab
 F ext/wasm/dist.make 481289899a07958439d07ee4302ff86235fa0fbb72f17ea05db2be90a94abf90
 F ext/wasm/fiddle.make e570ec1bfc7d803507a2e514fe32f673fe001b2114b85c73c3964a462ba8bcfc
 F ext/wasm/fiddle/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
@@ -546,10 +546,10 @@ F ext/wasm/split-speedtest1-script.sh a3e271938d4d14ee49105eb05567c6a69ba4c1f129
 F ext/wasm/sql/000-mandelbrot.sql 775337a4b80938ac8146aedf88808282f04d02d983d82675bd63d9c2d97a15f0
 F ext/wasm/sql/001-sudoku.sql 35b7cb7239ba5d5f193bc05ec379bcf66891bce6f2a5b3879f2f78d0917299b5
 F ext/wasm/test-opfs-vfs.html 1f2d672f3f3fce810dfd48a8d56914aba22e45c6834e262555e685bce3da8c3f
-F ext/wasm/test-opfs-vfs.js 48fc59110e8775bb43c9be25b6d634fc07ebadab7da8fbd44889e8129c6e2548
-F ext/wasm/tester1-worker.html d02b9d38876b023854cf8955e77a40912f7e516956b4dbe1ec7f215faac273ee
-F ext/wasm/tester1.html c6c47e5a8071eb09cb1301104435c8e44fbb5719c92411f5b2384a461f9793c5
-F ext/wasm/tester1.js 2427ac48e255f658ad81163b5dc6372a8609ab6ab60e295e371d1e5fe9a495ab
+F ext/wasm/test-opfs-vfs.js 44363db07b2a20e73b0eb1808de4400ca71b703af718d0fa6d962f15e73bf2ac
+F ext/wasm/tester1-worker.html 51bf39e2b87f974ae3d5bc3086e2fb36d258f3698c54f6e21ba4b3b99636fa27
+F ext/wasm/tester1.html 624ec41cd9f78a1f2b6d7df70aaa7a6394396b1f2455ecbd6de5775c1275b121
+F ext/wasm/tester1.js 157eb499aad3365e33a7d95d6847c1d58d533335bc19d79bd3bc700b6350d1a5
 F ext/wasm/version-info.c 3b36468a90faf1bbd59c65fd0eb66522d9f941eedd364fabccd72273503ae7d5
 F ext/wasm/wasmfs.make fb2d3c4a298b12cf1ec994ad1d0f1d027ae297449b364cde43d2eb807d68048f
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
@@ -2054,8 +2054,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P c7750c101d9b7baa31496731bc34ea0a9b2bad0c11e2b3e92a8c7b327135c1bb
-R 196f3951f65687c9f90c3fbde15932cd
-U drh
-Z 5dce30cfcdbfc3a472a813e27f5eb193
+P d15c9a4a323b825eb80e706e12e9df95e5db458024f51e6e537940efc8234d8b
+R 095ddbe256b2c65febf55a9bc126a8d9
+U stephan
+Z 25b125153b5de3e07d69ba6b59e3eede
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 0771c2adac..f229779db4 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d15c9a4a323b825eb80e706e12e9df95e5db458024f51e6e537940efc8234d8b
\ No newline at end of file
+86a341d7e061f946b39e8647ddd4743013b851b33ae9e6e755d8dbc53fba5286
\ No newline at end of file