Simplify (see Level/supports#1)

Level · Oct 6, 2019 · b36dafe · b36dafe
1 parent 2263d2f
commit b36dafe
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Showing 2 changed files with 55 additions and 56 deletions.
diff --git a/index.js b/index.js
@@ -6,22 +6,27 @@ var AbstractIterator = require('abstract-leveldown').AbstractIterator
 var inherits = require('inherits')
 var Codec = require('level-codec')
 var EncodingError = require('level-errors').EncodingError
-var specialMethods = ['approximateSize', 'compactRange']
+var rangeMethods = ['approximateSize', 'compactRange']
 
 module.exports = DB.default = DB
 
 function DB (db, opts) {
   if (!(this instanceof DB)) return new DB(db, opts)
-  if (db.supports && db.supports.encodings) throw new Error('Double encoding')
 
   AbstractLevelDOWN.call(this, db.supports)
   this.supports.encodings = true
 
-  // TODO (future major): remove this fallback
-  specialMethods.forEach(function (m) {
+  rangeMethods.forEach(function (m) {
+    // TODO (future major): remove this fallback
     if (typeof db[m] === 'function' && !this.supports.additionalMethods[m]) {
-      this.supports.additionalMethods[m] = {
-        args: [{ type: 'key' }, { type: 'key' }, { type: 'options' }]
+      this.supports.additionalMethods[m] = true
+    }
+
+    if (this.supports.additionalMethods[m]) {
+      this[m] = function (start, end, opts, cb) {
+        start = this.codec.encodeKey(start, opts)
+        end = this.codec.encodeKey(end, opts)
+        return this.db[m](start, end, opts, cb)
       }
     }
   }, this)
@@ -32,29 +37,6 @@ function DB (db, opts) {
 
   this.db = db
   this.codec = new Codec(opts)
-
-  Object.keys(this.supports.additionalMethods).forEach(function (m) {
-    if (this[m] != null) return
-
-    var signature = this.supports.additionalMethods[m]
-    var args = (signature && signature.args) || []
-
-    this[m] = function () {
-      var i = Math.min(arguments.length, args.length)
-      var opts
-
-      while (i--) {
-        if (args[i].type === 'options' && !opts && isOptions(arguments[i])) {
-          opts = arguments[i]
-          arguments[i] = this.codec.encodeLtgt(opts)
-        } else if (args[i].type === 'key') {
-          arguments[i] = this.codec.encodeKey(arguments[i], opts)
-        }
-      }
-
-      return this.db[m].apply(this.db, arguments)
-    }
-  }, this)
 }
 
 inherits(DB, AbstractLevelDOWN)
@@ -189,7 +171,3 @@ Batch.prototype._clear = function () {
 Batch.prototype._write = function (opts, cb) {
   this.batch.write(opts, cb)
 }
-
-function isOptions (o) {
-  return typeof o === 'object' && o !== null
-}
diff --git a/test/index.js b/test/index.js
@@ -579,47 +579,68 @@ test('iterator catches decoding error from valueEncoding', function (t) {
   })
 })
 
-test('encodes start and end of approximateSize()', function (t) {
-  t.plan(2)
+test('proxies approximateSize() if it exists', function (t) {
+  t.is(typeof encdown({ approximateSize: noop }).approximateSize, 'function')
+  t.ok(encdown({ approximateSize: noop }).supports.additionalMethods.approximateSize)
+  t.is(encdown({}).approximateSize, undefined)
+  t.notOk(encdown({}).supports.additionalMethods.approximateSize)
+  t.end()
+})
 
-  var down = {
+test('proxies compactRange() if it exists', function (t) {
+  t.is(typeof encdown({ compactRange: noop }).compactRange, 'function')
+  t.ok(encdown({ compactRange: noop }).supports.additionalMethods.compactRange)
+  t.is(encdown({}).compactRange, undefined)
+  t.notOk(encdown({}).supports.additionalMethods.compactRange)
+  t.end()
+})
+
+test('encodes start and end of approximateSize()', function (t) {
+  var db = encdown({
     approximateSize: function (start, end) {
       t.is(start, '1')
       t.is(end, '2')
+      t.end()
     }
-  }
+  })
 
-  encdown(down).approximateSize(1, 2, noop)
+  db.approximateSize(1, 2, noop)
 })
 
-test('encodes start and end of approximateSize() with custom encoding', function (t) {
-  t.plan(2)
+test('encodes start and end of compactRange()', function (t) {
+  var db = encdown({
+    compactRange: function (start, end) {
+      t.is(start, '1')
+      t.is(end, '2')
+      t.end()
+    }
+  })
 
-  var down = {
+  db.compactRange(1, 2, noop)
+})
+
+test('encodes start and end of approximateSize() with custom encoding', function (t) {
+  var db = encdown({
     approximateSize: function (start, end) {
       t.is(start, '"a"')
       t.is(end, '"b"')
+      t.end()
     }
-  }
+  })
 
-  encdown(down).approximateSize('a', 'b', { keyEncoding: 'json' }, noop)
+  db.approximateSize('a', 'b', { keyEncoding: 'json' }, noop)
 })
 
-test('encodes options of additionalMethod', function (t) {
-  t.plan(1)
-
-  var down = {
-    supports: {
-      additionalMethods: {
-        foo: { args: [{ type: 'options' }] }
-      }
-    },
-    foo: function (options) {
-      t.is(options.gt, '"a"')
+test('encodes start and end of compactRange() with custom encoding', function (t) {
+  var db = encdown({
+    compactRange: function (start, end) {
+      t.is(start, '"a"')
+      t.is(end, '"b"')
+      t.end()
     }
-  }
+  })
 
-  encdown(down).foo({ gt: 'a', keyEncoding: 'json' })
+  db.compactRange('a', 'b', { keyEncoding: 'json' }, noop)
 })
 
 test('encodes seek target', function (t) {