fix: style, coverage, docs for completeGraph

Author: rvagg

README.md

@@ -76,6 +76,7 @@ Other create-modes may be supported in the future, such as writing to a Buffer (
  * [`async CarDatastore.readStreamComplete(stream)`](#CarDatastore__readStreamComplete)
  * [`async CarDatastore.readStreaming(stream)`](#CarDatastore__readStreaming)
  * [`async CarDatastore.writeStream(stream)`](#CarDatastore__writeStream)
+ * [`async CarDatastore.completeGraph(root, get, car[, concurrency])`](#CarDatastore__completeGraph)
  * [`class CarDatastore`](#CarDatastore)
  * [`async CarDatastore#get(key)`](#CarDatastore_get)
  * [`async CarDatastore#has(key)`](#CarDatastore_has)
@@ -215,6 +216,24 @@ This create-mode is not available in a browser environment.
 
 **Return value**  _(`CarDatastore`)_: an append-only, streaming CarDatastore.
 
+<a name="CarDatastore__completeGraph"></a>
+### `async CarDatastore.completeGraph(root, get, car[, concurrency])`
+
+Read a complete IPLD graph from a provided datastore and store the blocks in
+a CAR file.
+
+**Parameters:**
+
+* **`root`** _(`Block`)_: the root of the graph to start at, this block will be
+  included in the CAR and its CID will be set as the single root.
+* **`get`** _(`AsyncFunction`)_: an `async` function that takes a CID and returns
+  a `Block`. Can be used to attach to an arbitrary data store.
+* **`car`** _(`CarDatastore`)_: a writable `CarDatastore` that has not yet been
+  written to (`setRoots()` will be called on it which requires that no data
+  has been written).
+* **`concurrency`** _(`number`, optional, default=`1`)_: how many asynchronous `get` operations to
+  perform at once.
+
 <a name="CarDatastore"></a>
 ### `class CarDatastore`
 

car.js

@@ -139,10 +139,13 @@ async function traverseBlock (block, get, car, concurrency = 1, seen = new Set()
   const cid = await block.cid()
   await car.put(cid, block.encodeUnsafe())
   seen.add(cid.toString('base58btc'))
-  if (cid.codec === 'raw') return
+  if (cid.codec === 'raw') {
+    return
+  }
   const reader = block.reader()
-  const missing = link => !seen.has(link.toString('base58btc'))
+  const missing = (link) => !seen.has(link.toString('base58btc'))
   const links = Array.from(reader.links()).filter(missing).map(([, link]) => link)
+
   while (links.length) {
     const chunk = links.splice(0, concurrency)
     const blocks = chunk.map(get)
@@ -156,6 +159,25 @@ async function traverseBlock (block, get, car, concurrency = 1, seen = new Set()
   }
 }
 
+/**
+ * @name CarDatastore.completeGraph
+ * @description
+ * Read a complete IPLD graph from a provided datastore and store the blocks in
+ * a CAR file.
+ * @function
+ * @memberof CarDatastore
+ * @static
+ * @async
+ * @param {Block} root the root of the graph to start at, this block will be
+ * included in the CAR and its CID will be set as the single root.
+ * @param {AsyncFunction} get an `async` function that takes a CID and returns
+ * a `Block`. Can be used to attach to an arbitrary data store.
+ * @param {CarDatastore} car a writable `CarDatastore` that has not yet been
+ * written to (`setRoots()` will be called on it which requires that no data
+ * has been written).
+ * @param {number} [concurrency=1] how many asynchronous `get` operations to
+ * perform at once.
+ */
 async function completeGraph (root, get, car, concurrency) {
   await car.setRoots([root])
   await traverseBlock(await get(root), get, car, concurrency)

datastore.js

@@ -150,6 +150,7 @@ class CarDatastore {
   }
 
   async batch () {
+    /* c8 ignore next */
     throw new Error('Unimplemented operation')
   }
 

lib/coding.js

@@ -215,7 +215,8 @@ function encodeStream (roots, blocks) {
   encode(writer, roots, blocks)
     .then(() => {
       stream.end()
-    }).catch(/* istanbul ignore next toohard */ (err) => {
+    }).catch((err) => {
+      /* c8 ignore next 3 */
       // maybe this could end up being recursive, with the promise rejection
       // above, depending on conditions?
       stream.emit('error', err)
@@ -227,7 +228,7 @@ function createStreamWriter (stream) {
   return (buf) => {
     return new Promise((resolve, reject) => {
       stream.write(buf, (err) => {
-        // istanbul ignore next toohard
+        /* c8 ignore next 3 */
         if (err) {
           reject(err)
         }

lib/reader-writer-iface.js

@@ -2,17 +2,17 @@ const { Errors } = require('interface-datastore')
 const { verifyRoots, cidToKey } = require('./util')
 
 class Reader {
-  // istanbul ignore next
+  /* c8 ignore next 3 */
   get () {
     throw new Error('Unimplemented method')
   }
 
-  // istanbul ignore next
+  /* c8 ignore next 3 */
   has () {
     throw new Error('Unimplemented method')
   }
 
-  // istanbul ignore next
+  /* c8 ignore next 3 */
   keys () {
     throw new Error('Unimplemented method')
   }

lib/writer-stream.js

@@ -13,7 +13,7 @@ class StreamWriter extends Writer {
   }
 
   /* async */ setRoots (roots) {
-    // istanbul ignore next toohard
+    /* c8 ignore next 3 */
     if (this._mutex) {
       throw new Error('Roots already set or blocks are being written')
     }

package.json

@@ -12,7 +12,8 @@
     "test:browser": "npx polendina --cleanup test/test-readbuffer.js test/test-query.js",
     "test:node": "hundreds mocha test/test-*.js",
     "test": "npm run lint && npm run test:node && npm run test:browser",
-    "docs": "npx jsdoc4readme --readme *.js lib/raw.js"
+    "docs": "npx jsdoc4readme --readme *.js lib/raw.js",
+    "coverage": "c8 --reporter=html --reporter=text mocha test/test-*.js && npx st -d coverage -p 8888"
   },
   "repository": {
     "type": "git",
@@ -32,13 +33,13 @@
   "devDependencies": {
     "bl": "^4.0.2",
     "garbage": "0.0.0",
-    "hundreds": "0.0.2",
-    "mocha": "^7.1.1"
+    "hundreds": "0.0.7",
+    "mocha": "^7.2.0"
   },
   "dependencies": {
     "@ipld/block": "^4.0.0",
     "cids": "^0.8.0",
-    "interface-datastore": "^0.8.3",
+    "interface-datastore": "^1.0.4",
     "multicodec": "^1.0.1",
     "varint": "^5.0.0"
   }

test/test-complete-graph.js

@@ -7,33 +7,38 @@ const { PassThrough } = require('stream')
 
 const same = assert.deepStrictEqual
 
-const all = car => {
+function all (car) {
   const _traverse = async function * (link, seen = new Set()) {
     link = await link
     seen.add(link.toString('base64'))
     const encoded = await car.get(link)
     const block = Block.create(encoded, link)
     yield block
     const cid = await block.cid()
-    if (cid.codec === 'raw') return
+    if (cid.codec === 'raw') {
+      return
+    }
+
     for (const [, link] of block.reader().links()) {
-      if (seen.has(link.toString('base64'))) continue
+      if (seen.has(link.toString('base64'))) {
+        continue
+      }
       yield * _traverse(link, seen)
     }
   }
 
   return _traverse(car.getRoots().then(([root]) => root))
 }
 
-const createGet = async blocks => {
+async function createGet (blocks) {
   const db = new Map()
   for (const block of blocks) {
     db.set((await block.cid()).toString('base64'), block)
   }
-  return cid => new Promise(resolve => resolve(db.get(cid.toString('base64'))))
+  return (cid) => new Promise((resolve) => resolve(db.get(cid.toString('base64'))))
 }
 
-const concat = async stream => {
+async function concat (stream) {
   const buffers = []
   for await (const buffer of stream) {
     buffers.push(buffer)

test/test-raw.js

@@ -78,7 +78,7 @@ describe('Raw', () => {
 
   it('read raw using index (FileHandle)', async () => {
     const fd = await fs.promises.open(path.join(__dirname, 'go.car'))
-    verifyRead(fd)
+    await verifyRead(fd)
     await fd.close(fd)
   })