5 files changed, 145 insertions, 0 deletions
diff --git a/dom/fs/test/common/test_writableFileStream.js b/dom/fs/test/common/test_writableFileStream.js
index 016c53bf3b..5b6caa0d20 100644
--- a/dom/fs/test/common/test_writableFileStream.js
+++ b/dom/fs/test/common/test_writableFileStream.js
@@ -2,6 +2,7 @@
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 const allowCreate = { create: true };
+const denyCreate = { create: false };
 
 exported_symbols.test0 = async function () {
   let root = await navigator.storage.getDirectory();
@@ -145,6 +146,111 @@ exported_symbols.bug1825018 = async function () {
   }
 };
 
+exported_symbols.usageTest = async function () {
+  const bufferSize = 1024;
+  const keepData = { keepExistingData: true };
+  const fromEmpty = { keepExistingData: false };
+
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  const baseUsage = await Utils.getCachedOriginUsage();
+  Assert.ok(true, "Usage " + baseUsage);
+  // Create a file.
+  {
+    const fileHandle = await root.getFileHandle("usagetest.txt", allowCreate);
+    Assert.ok(!!fileHandle, "Can we get file handle?");
+
+    const writable = await fileHandle.createWritable(fromEmpty);
+    Assert.ok(!!writable, "Can we create writable file stream?");
+
+    const buffer = new ArrayBuffer(bufferSize);
+    Assert.ok(!!buffer, "Can we create array buffer?");
+
+    const result = await writable.write(buffer);
+    Assert.equal(result, undefined, "Can we write entire buffer?");
+
+    await writable.close();
+  }
+
+  {
+    const fileUsage = await Utils.getCachedOriginUsage();
+    Assert.ok(true, "Usage " + fileUsage);
+    Assert.ok(fileUsage >= baseUsage + bufferSize);
+
+    const fileHandle = await root.getFileHandle("usagetest.txt", denyCreate);
+    Assert.ok(!!fileHandle, "Can we get file handle?");
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage);
+    }
+
+    const writableA = await fileHandle.createWritable(keepData);
+    Assert.ok(!!writableA, "Can we create writable file stream?");
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.ok(true, "Usage " + usageNow.usage);
+      Assert.equal(usageNow, fileUsage + bufferSize);
+    }
+
+    const writableB = await fileHandle.createWritable(keepData);
+    Assert.ok(!!writableB, "Can we create writable file stream?");
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage + 2 * bufferSize);
+    }
+
+    const writableC = await fileHandle.createWritable(keepData);
+    Assert.ok(!!writableC, "Can we create writable file stream?");
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage + 3 * bufferSize);
+    }
+
+    const writableD = await fileHandle.createWritable(fromEmpty);
+    Assert.ok(!!writableD, "Can we create writable file stream?");
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      // We did not keep existing data for this writable
+      Assert.equal(usageNow, fileUsage + 3 * bufferSize);
+    }
+
+    await writableA.abort();
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage + 2 * bufferSize);
+    }
+
+    await writableB.close();
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage + bufferSize);
+    }
+
+    await writableC.abort();
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      Assert.equal(usageNow, fileUsage);
+    }
+
+    await writableD.close();
+
+    {
+      const usageNow = await Utils.getCachedOriginUsage();
+      // Buffer was overwritten with nothing.
+      Assert.equal(usageNow, fileUsage - bufferSize);
+    }
+  }
+};
+
 for (const [key, value] of Object.entries(exported_symbols)) {
   Object.defineProperty(value, "name", {
     value: key,
diff --git a/dom/fs/test/crashtests/1874334-2.html b/dom/fs/test/crashtests/1874334-2.html
new file mode 100644
index 0000000000..3d30d7496f
--- /dev/null
+++ b/dom/fs/test/crashtests/1874334-2.html
@@ -0,0 +1,8 @@
+<script>
+document.addEventListener("DOMContentLoaded", async () => {
+    await self.navigator.serviceWorker.register("sw1874334-2.js?318", { })
+    await self.navigator.serviceWorker.register("sw1874334-2.js?363", { })
+    await self.navigator.serviceWorker.register("sw1874334-2.js?87", { })
+    await self.fetch("missing", {"headers": []})
+})
+</script>
diff --git a/dom/fs/test/crashtests/1874334.html b/dom/fs/test/crashtests/1874334.html
new file mode 100644
index 0000000000..590025a60f
--- /dev/null
+++ b/dom/fs/test/crashtests/1874334.html
@@ -0,0 +1,16 @@
+<script>
+
+async function stuff() {
+    let arr = new ArrayBuffer(500000);
+    let blob = new Blob([arr]);
+    let file = new File([blob], "", { });
+
+    let dir = await self.navigator.storage.getDirectory();
+    let handle = await dir.getFileHandle("514600c6-596b-4676-ab0c-3e6f1e86759f", {"create": true});
+    let wfs = await handle.createWritable({"keepExistingData": true});
+
+    await file.stream().pipeTo(wfs);
+};
+
+document.addEventListener("DOMContentLoaded", stuff);
+</script>
diff --git a/dom/fs/test/crashtests/crashtests.list b/dom/fs/test/crashtests/crashtests.list
index a083cb80b2..c5130c4232 100644
--- a/dom/fs/test/crashtests/crashtests.list
+++ b/dom/fs/test/crashtests/crashtests.list
@@ -1,6 +1,7 @@
 # StorageManager isn't enabled on Android
 defaults skip-if(Android) pref(dom.fs.enabled,true) pref(dom.fs.writable_file_stream.enabled,true)
 
+# Most of the issues here are reproducible only with --verify
 load 1798773.html
 load 1800470.html
 load 1809759.html
@@ -8,3 +9,5 @@ load 1816710.html
 load 1841702.html
 HTTP load 1844619.html
 HTTP load 1858820.html
+load 1874334.html
+HTTP load 1874334-2.html
diff --git a/dom/fs/test/crashtests/sw1874334-2.js b/dom/fs/test/crashtests/sw1874334-2.js
new file mode 100644
index 0000000000..59d82ebaaa
--- /dev/null
+++ b/dom/fs/test/crashtests/sw1874334-2.js
@@ -0,0 +1,12 @@
+(async () => {
+    let arr = new ArrayBuffer(43109)
+    let blob = new Blob([arr, arr, arr, arr, arr])
+    let req = new Request("missing", {"headers": []})
+    let dir = await self.navigator.storage.getDirectory()
+    let file = new File([blob, arr], "", { })
+    let handle = await dir.getFileHandle("514600c6-596b-4676-ab0c-3e6f1e86759f", {"create": true})
+    let wfs = await handle.createWritable({"keepExistingData": true})
+    await handle.createWritable({"keepExistingData": true})
+    try { await req.json(arr, {"headers": []}) } catch (e) {}
+    try { await file.stream().pipeTo(wfs, { }) } catch (e) {}
+})()