Handle modules that cannot be loaded in node

If there is some error when requiering a module that is not that the
module does not exist, we know that we have found the right path. It is
therefore returned with a fake module instance.

This should be considered experimental but will unlock some blocked use
cases.

lib/find-module.coffee

@@ -17,10 +17,15 @@ tryFind = (base, fileName, callers) ->
     instance: require fileName
     path: fileName
   catch e
-    try
-      findModule(base, fileName, callers)
-    catch e2
-      throw new CouldNotLoad base, fileName, callers
+    if e.code == 'MODULE_NOT_FOUND'
+      try
+        findModule(base, fileName, callers)
+      catch e2
+        throw new CouldNotLoad base, fileName, callers
+    else
+      instance: {}
+      path: makePath base, fileName, callers
+
 
 exports.instance = (base, fileName, callers) ->
   tryFind(base, fileName, callers).instance

package.json

@@ -15,6 +15,7 @@
     "coffee-script": "^1.9.0",
     "mocha": "^5.0.0",
     "mocha-gwt": "^0.2.0",
+    "pikaday": "^1.7.0",
     "ramda": "^0.25.0",
     "source-map-support": "^0.5.2"
   },

test/e2e/find-module-test.coffee

@@ -15,8 +15,9 @@ describe 'findModule', ->
 
   verifyResult = ->
     (@base + '/' + @expectedPath).should.equal @resultPath
-    expectedInstance = req @expectedPath
-    expectedInstance.should.deep.equal @resultInstance
+    unless @expectedInstance?
+      @expectedInstance = req @expectedPath
+    @expectedInstance.should.deep.equal @resultInstance
 
   afterBlock ->
     if @error?
@@ -72,3 +73,11 @@ describe 'findModule', ->
       @fileName = 'nonExisting'
       @callers = [ 'fake2', 'fake3' ]
     Then -> @error?
+
+  describe 'troublesome module', ->
+    Given ->
+      @expectedInstance = {}
+      @expectedPath = 'node_modules/pikaday'
+      @fileName = 'pikaday'
+      @callers = []
+    Then verifyResult