test: more chain/wrap behavior tests

test/chain.coffee

@@ -3,8 +3,16 @@ async = require 'async'
 _s = require "#{__dirname}/../index"
 sinon = require 'sinon'
 
-describe '_s(a).chain().fn1(b).fn2(c).value()', ->
-  it 'is equivalent to calling _s.fn2(_s.fn1(a, b), c)', ->
+describe '_s(a).chain()', ->
+  it "has the methods of _s", ->
+    assert _s().chain().each?
+    assert _s('a').chain().each?
+
+  it '.value() returns a', ->
+    assert.equal _s().chain().value(), undefined
+    assert.equal _s('a').chain().value(), 'a'
+
+  it '.fn1(b).fn2(c).value() is equivalent to calling _s.fn2(_s.fn1(a, b), c)', ->
     spy1 = sinon.spy -> 1
     spy2 = sinon.spy -> 2
     _s.mixin {fn1: spy1, fn2: spy2}

test/wrap.coffee

@@ -3,12 +3,39 @@ async = require 'async'
 _s = require "#{__dirname}/../index"
 sinon = require 'sinon'
 
-describe '_s(a).fn(b)', ->
-  it 'is equivalent to calling _s.fn(a,b)', ->
+describe '_s(a)', ->
+  it 'has the methods of _s', ->
+    assert _s().each?
+    assert _s('a').each?
+
+  it 'binds a as the first argument to the next method invoked', ->
+    spy = sinon.spy ->
+    _s.mixin fn: spy
+    _s().fn(10)
+    _s().fn(10, 20)
+    _s('a').fn(10)
+    _s('a').fn(10, 20)
+    _s('a', 'b').fn(10)
+    _s('a', 'b').fn(10, 20)
+    assert.equal spy.callCount, 6
+    assert.deepEqual spy.args, [
+      [undefined, 10]
+      [undefined, 10, 20]
+      ['a', 10]
+      ['a', 10, 20]
+      ['a', 10]      # ignores > 1 argument
+      ['a', 10, 20]  # ignores > 1 argument
+    ]
+
+  it '.fn(b) is equivalent to calling _s.fn(a,b)', ->
     spy = sinon.spy ->
     _s.mixin fn: spy
     _s.fn 'a', 'b'
     _s('a').fn('b')
     assert.equal spy.callCount, 2
     assert.deepEqual spy.args[0], ['a', 'b']
     assert.deepEqual spy.args[0], spy.args[1]
+
+  it '.missing() throws', ->
+    assert.throws () ->
+      _s('a').missing()