fix: strip trailing slash from car file name (#290)

Otherwise filenames end up being Qmfoo_.car instead of Qmfoo.car

Author: achingbrain

packages/verified-fetch/src/plugins/plugin-handle-car.ts

@@ -17,6 +17,7 @@ function getFilename ({ cid, ipfsPath, query }: Pick<PluginContext, 'query' | 'c
   const filename = ipfsPath
     .replace(/\/ipfs\//, '')
     .replace(/\/ipns\//, '')
+    .replace(/\/+$/g, '')
     .replace(/\//g, '_')
 
   return `${filename}.car`

packages/verified-fetch/test/content-disposition.spec.ts

@@ -56,4 +56,46 @@ describe('content-disposition', () => {
     expect(resp.status).to.equal(200)
     expect(resp.headers.get('Content-Disposition')).to.include('attachment')
   })
+
+  it('should default to the CID for the car file name', async () => {
+    const obj = {
+      hello: 'world'
+    }
+    const c = dagCbor(helia)
+    const cid = await c.add(obj)
+
+    const resp = await fetch(`ipfs://${cid}/?format=car`)
+    expect(resp).to.be.ok()
+    expect(resp.status).to.equal(200)
+    expect(resp.headers.get('Content-Disposition')).to.include('attachment')
+    expect(resp.headers.get('Content-Disposition')).to.include(`filename="${cid}.car"`)
+  })
+
+  it('should respect a filename for the car file name', async () => {
+    const obj = {
+      hello: 'world'
+    }
+    const c = dagCbor(helia)
+    const cid = await c.add(obj)
+
+    const resp = await fetch(`ipfs://${cid}/?filename=my-car.car&format=car`)
+    expect(resp).to.be.ok()
+    expect(resp.status).to.equal(200)
+    expect(resp.headers.get('Content-Disposition')).to.include('attachment')
+    expect(resp.headers.get('Content-Disposition')).to.include('filename="my-car.car"')
+  })
+
+  it('should respect a filename for the car file name with many trailing slashes', async () => {
+    const obj = {
+      hello: 'world'
+    }
+    const c = dagCbor(helia)
+    const cid = await c.add(obj)
+
+    const resp = await fetch(`ipfs://${cid}///////?filename=my-car.car&format=car`)
+    expect(resp).to.be.ok()
+    expect(resp.status).to.equal(200)
+    expect(resp.headers.get('Content-Disposition')).to.include('attachment')
+    expect(resp.headers.get('Content-Disposition')).to.include('filename="my-car.car"')
+  })
 })