Feat/err codes

package.json

@@ -34,16 +34,17 @@
   },
   "homepage": "https://github.com/ipfs/interface-datastore#readme",
   "devDependencies": {
-    "aegir": "^12.2.0",
+    "aegir": "^15.1.0",
     "chai": "^4.1.2",
     "dirty-chai": "^2.0.1",
-    "flow-bin": "^0.60.1"
+    "flow-bin": "~0.60.1"
   },
   "dependencies": {
-    "async": "^2.6.0",
-    "pull-defer": "^0.2.2",
-    "pull-stream": "^3.6.1",
-    "uuid": "^3.1.0"
+    "async": "^2.6.1",
+    "err-code": "^1.1.2",
+    "pull-defer": "~0.2.3",
+    "pull-stream": "^3.6.9",
+    "uuid": "^3.3.2"
   },
   "engines": {
     "node": ">=6.0.0",

src/errors.js

@@ -0,0 +1,23 @@
+'use strict'
+
+const errcode = require('err-code')
+
+module.exports.dbOpenFailedError = (err) => {
+  err = err || new Error('Cannot open database')
+  return errcode(err, 'ERR_DB_OPEN_FAILED')
+}
+
+module.exports.dbDeleteFailedError = (err) => {
+  err = err || new Error('Delete failed')
+  return errcode(err, 'ERR_DB_DELETE_FAILED')
+}
+
+module.exports.dbWriteFailedError = (err) => {
+  err = err || new Error('Write failed')
+  return errcode(err, 'ERR_DB_WRITE_FAILED')
+}
+
+module.exports.notFoundError = (err) => {
+  err = err || new Error('Not Found')
+  return errcode(err, 'ERR_NOT_FOUND')
+}

src/index.js

@@ -4,10 +4,12 @@
 const Key = require('./key')
 const MemoryDatastore = require('./memory')
 const utils = require('./utils')
+const Errors = require('./errors')
 
 exports.Key = Key
 exports.MemoryDatastore = MemoryDatastore
 exports.utils = utils
+exports.Errors = Errors
 
 /* ::
 // -- Basics

src/memory.js

@@ -10,6 +10,9 @@ const asyncFilter = require('./utils').asyncFilter
 const asyncSort = require('./utils').asyncSort
 const Key = require('./key')
 
+// Errors
+const Errors = require('./errors')
+
 class MemoryDatastore {
   /* :: data: {[key: string]: Buffer} */
 
@@ -34,7 +37,7 @@ class MemoryDatastore {
       }
 
       if (!exists) {
-        return callback(new Error('No value'))
+        return callback(Errors.notFoundError())
       }
 
       callback(null, this.data[key.toString()])

src/tests.js

@@ -111,6 +111,15 @@ module.exports = (test/* : Test */) => {
         })
       ], done)
     })
+
+    it('should return error with missing key', (done) => {
+      const k = new Key('/does/not/exist')
+      check(store).get(k, (err) => {
+        expect(err).to.exist()
+        expect(err).to.have.property('code', 'ERR_NOT_FOUND')
+        done()
+      })
+    })
   })
 
   describe('delete', () => {