Improve friendly string name of tdFunctions

Instead of merely Stringifying the function names, we can intelligently
emit the string name in a form that's idiomatic to the type of key the
function is defined under. Methods are prefixed with `.` or `#`; Symbol
keys are wrapped in brackets `[]`.

Author: jasonkarns

regression/src/constructor-test.coffee

@@ -81,7 +81,7 @@ describe 'td.constructor', ->
     And -> td.explain(@fakeInstance[@symbolFoo]).isTestDouble == true
     And -> @fakeConstructor.toString() == '[test double for "(unnamed constructor)"]'
     And -> @fakeInstance.toString() == '[test double instance of constructor]'
-    And -> @fakeInstance[@symbolFoo].toString() == '[test double for "#Symbol(foo)"]'
+    And -> @fakeInstance[@symbolFoo].toString() == '[test double for "#[Symbol(foo)]"]'
 
   describe 'edge case: being given a function without prototypal methods', ->
     Given -> @boringFunc = ->

regression/src/object-test.coffee

@@ -31,7 +31,7 @@ describe 'td.object', ->
     When -> td.when(@testDouble[@symbolFoo]()).thenReturn('zing!')
     Then -> @testDouble[@symbolFoo]() == 'zing!'
     And -> @testDouble.toString() == '[test double object]'
-    And -> @testDouble[@symbolFoo].toString() == '[test double for ".Symbol(foo)"]'
+    And -> @testDouble[@symbolFoo].toString() == '[test double for "[Symbol(foo)]"]'
 
   describe 'passing a function to td.object erroneously (1.x)', ->
     When -> try td.object(->) catch e then @result = e
@@ -62,7 +62,7 @@ describe 'td.object', ->
         Then -> @testDouble.lol.toString() == '[test double for ".lol"]'
 
       context 'with Symbol propKey', ->
-        And -> @testDouble[Symbol('foo')].toString() == '[test double for "thing.Symbol(foo)"]'
+        And -> @testDouble[Symbol('foo')].toString() == '[test double for "thing[Symbol(foo)]"]'
 
   else
     describe 'getting an error message', ->

src/constructor.js

@@ -13,7 +13,9 @@ var fakeConstructorFromNames = (funcNames) => {
       '[test double instance of constructor]'
 
     _.each(funcNames, (funcName) => {
-      fakeConstructor.prototype[funcName] = tdFunction(`#${String(funcName)}`)
+      fakeConstructor.prototype[funcName] = tdFunction(friendlyNameFor(funcName))
     })
   })
 }
+
+var friendlyNameFor = (name) => (typeof name === 'symbol') ? `#[${String(name)}]` : `#${String(name)}`

src/imitate/create-imitation.js

@@ -11,9 +11,10 @@ export default (original, names) => {
       return original
     } else {
       // TODO: this will become src/function/create and include parent reference instead of name joining here
-      return tdFunction(names.map(String).join('') || '(anonymous function)')
+      return tdFunction(names.map(friendlyName).join('') || '(anonymous function)')
     }
   } else {
     return _.clone(original)
   }
 }
+var friendlyName = (name) => (typeof name === 'symbol') ? `[${String(name)}]` : String(name)

src/object.js

@@ -26,7 +26,7 @@ var fakeObject = (nameOrType, config) => {
 
 var createTestDoublesForFunctionNames = (names) =>
   _.transform(names, (acc, funcName) => {
-    acc[funcName] = tdFunction(`.${String(funcName)}`)
+    acc[funcName] = tdFunction(friendlyNameFor(funcName))
   })
 
 var createTestDoubleViaProxy = (name, config) => {
@@ -35,13 +35,15 @@ var createTestDoubleViaProxy = (name, config) => {
   return new Proxy(obj, {
     get (target, propKey, receiver) {
       if (!obj.hasOwnProperty(propKey) && !_.includes(config.excludeMethods, propKey)) {
-        obj[propKey] = tdFunction(`${nameOf(name)}.${String(propKey)}`)
+        obj[propKey] = tdFunction(`${nameOf(name)}${friendlyNameFor(propKey)}`)
       }
       return obj[propKey]
     }
   })
 }
 
+var friendlyNameFor = (name) => (typeof name === 'symbol') ? `[${String(name)}]` : `.${String(name)}`
+
 var ensureProxySupport = (name) => {
   if (typeof Proxy === 'undefined') {
     log.error('td.object', `\

test/unit/imitate/create-imitation.test.js

@@ -34,7 +34,7 @@ module.exports = {
     const someFunc = () => {}
     const symFoo = Symbol('foo')
     const symBar = Symbol('bar')
-    td.when(tdFunction('Symbol(foo)Symbol(bar)'))
+    td.when(tdFunction('[Symbol(foo)][Symbol(bar)]'))
       .thenReturn('fake thing')
     td.when(isGenerator(someFunc)).thenReturn(false)