fix: implement .has method from the blockstore interface (#520)

Chains through to the wrapped blockstore.

Author: achingbrain

package.json

@@ -208,7 +208,7 @@
     "iso-random-stream": "^2.0.0",
     "it-all": "^2.0.0",
     "it-drain": "^2.0.0",
-    "libp2p": "next",
+    "libp2p": "^0.42.0",
     "lodash.difference": "^4.5.0",
     "lodash.flatten": "^4.4.0",
     "lodash.range": "^3.2.0",

src/bitswap.js

@@ -455,4 +455,12 @@ export class Bitswap extends BaseBlockstore {
   unwrap () {
     return this.blockstore
   }
+
+  /**
+   * @param {CID} cid
+   * @returns {Promise<boolean>}
+   */
+  has (cid) {
+    return this.blockstore.has(cid)
+  }
 }

test/bitswap.js

@@ -53,6 +53,30 @@ describe('start/stop', () => {
   })
 })
 
+describe('blockstore', () => {
+  it('should support .has', async () => {
+    const [block] = await makeBlocks(1)
+    const libp2p = {
+      handle: () => {},
+      unhandle: () => {},
+      register: () => {},
+      unregister: () => {},
+      getConnections: () => []
+    }
+    // @ts-ignore not a full libp2p
+    const bitswap = new Bitswap(libp2p, new MemoryBlockstore())
+    await bitswap.start()
+
+    await expect(bitswap.has(block.cid)).to.eventually.be.false()
+
+    await bitswap.put(block.cid, block.data)
+
+    await expect(bitswap.has(block.cid)).to.eventually.be.true()
+
+    await bitswap.stop()
+  })
+})
+
 describe('bitswap without DHT', function () {
   this.timeout(20 * 1000)