Method for fetching local or remote metadata files

.gitignore

@@ -7,13 +7,18 @@
 !bin/fetch-configlet
 !LICENSE
 !Makefile
+!generator/
 
-# make sure to ignore others
+# double ignore others
 *.swp
 .crystal/
 .DS_Store
 bin/configlet
 bin/configlet.exe
 CHECKLIST
 tmp/
-bin/generate
+bin/generator
+cache/
+generator/lib
+generator/.shards
+generator/bin/generator

Makefile

@@ -1,34 +1,51 @@
 EXERCISE ?= ""
 IGNOREDIRS := "^(\.git|.crystal|docs|bin|img|script)$$"
 EXERCISESDIR ?= "exercises"
-GENERATORDIR ?= "src/generator"
 EXERCISES = $(shell find exercises -maxdepth 1 -mindepth 1 -type d | cut -d'/' -f2 | sort | grep -Ev $(IGNOREDIRS))
 
 FILEEXT = "cr"
 SPECDIR = "spec"
 EXERCISENAME := "$(subst -,_,$(EXERCISE))"
-EXERCISEDIR := $(EXERCISESDIR)/$(EXERCISE)
-EXERCISESPECDIR := $(EXERCISEDIR)/$(SPECDIR)
+EXERCISESPECDIR := $(EXERCISESDIR)/$(EXERCISE)/$(SPECDIR)
 SPECFILE := "$(EXERCISENAME)_spec.$(FILEEXT)"
-SUPERTMPSPECFILE := "$(SPECFILE).super.tmp"
+SUPERSPECFILE := "$(SPECFILE).super"
 TMPSPECFILE := "$(SPECFILE).tmp"
 
+GENERATORDIR ?= "generator"
+GENERATORSDIR := $(GENERATORDIR)/src/generators
+GENERATORS = $(shell find $(GENERATORSDIR) -type f | cut -d '/' -f 4 | cut -d '.' -f 1 | sed 's/_/-/g')
+
 test-exercise:
 	@echo "running formatting check for: $(EXERCISE)"
 	@crystal tool format --check $(EXERCISESDIR)/$(EXERCISE)
+	@echo "moving files around"
 	@sed 's/pending/it/g' $(EXERCISESPECDIR)/$(SPECFILE) > $(EXERCISESPECDIR)/$(TMPSPECFILE)
-	@mv $(EXERCISESPECDIR)/$(SPECFILE) $(EXERCISESPECDIR)/$(SUPERTMPSPECFILE)
+	@mv $(EXERCISESPECDIR)/$(SPECFILE) $(EXERCISESPECDIR)/$(SUPERSPECFILE)
 	@mv $(EXERCISESPECDIR)/$(TMPSPECFILE) $(EXERCISESPECDIR)/$(SPECFILE)
 	@echo "running tests for: $(EXERCISE)"
 	@cd $(EXERCISESDIR)/$(EXERCISE) && crystal spec
 	@rm $(EXERCISESPECDIR)/$(SPECFILE)
-	@mv $(EXERCISESPECDIR)/$(SUPERTMPSPECFILE) $(EXERCISESPECDIR)/$(SPECFILE)
+	@mv $(EXERCISESPECDIR)/$(SUPERSPECFILE) $(EXERCISESPECDIR)/$(SPECFILE)
 	@printf "\n"
 
-test:
+test-exercises:
 	@for exercise in $(EXERCISES); do EXERCISE=$$exercise $(MAKE) -s test-exercise || exit 1; done
+
+build-generator:
+	@crystal build $(GENERATORDIR)/generator.$(FILEEXT) -o generator/bin/generator
+
+generate-exercise:
+	@echo "generating spec file for generator: $(GENERATOR)"
+	@generator/bin/generator $(GENERATOR)
+
+generate-exercises:
+	@for generator in $(GENERATORS); do GENERATOR=$$generator $(MAKE) -s generate-exercise || exit 1; done
+
+test-generator:
 	@echo "running generator tests"
-	@cd $(GENERATORDIR) && crystal spec
+	@cd $(GENERATORDIR) && crystal deps && crystal spec
 
-build_generator:
-	@crystal build $(GENERATORDIR)/generate.$(FILEEXT) -o bin/generate
+test:
+	@echo "running all the tests"
+	@$(MAKE) -s test-exercises
+	@$(MAKE) -s test-generator

config.json

@@ -160,6 +160,13 @@
       "difficulty": 3,
       "topics": [
 
+      ]
+    },
+    {
+      "slug": "flatten-array",
+      "difficulty": 1,
+      "topics": [
+
       ]
     }
   ],

exercises/flatten-array/spec/flatten_array_spec.cr

@@ -0,0 +1,28 @@
+require "spec"
+require "../src/*"
+
+describe "FlattenArray" do
+  it "no nesting" do
+    FlattenArray.flatten([0, 1, 2]).should eq([0, 1, 2])
+  end
+
+  pending "flattens array with just integers present" do
+    FlattenArray.flatten([1, [2, 3, 4, 5, 6, 7], 8]).should eq([1, 2, 3, 4, 5, 6, 7, 8])
+  end
+
+  pending "5 level nesting" do
+    FlattenArray.flatten([0, 2, [[2, 3], 8, 100, 4, [[[50]]]], -2]).should eq([0, 2, 2, 3, 8, 100, 4, 50, -2])
+  end
+
+  pending "6 level nesting" do
+    FlattenArray.flatten([1, [2, [[3]], [4, [[5]]], 6, 7], 8]).should eq([1, 2, 3, 4, 5, 6, 7, 8])
+  end
+
+  pending "6 level nest list with null values" do
+    FlattenArray.flatten([0, 2, [[2, 3], 8, [[100]], nil, [[nil]]], -2]).should eq([0, 2, 2, 3, 8, 100, -2])
+  end
+
+  pending "all values in nested list are null" do
+    FlattenArray.flatten([nil, [[[nil]]], nil, nil, [[nil, nil], nil], nil]).should eq([] of Nil)
+  end
+end

exercises/flatten-array/src/example.cr

@@ -0,0 +1,7 @@
+module FlattenArray
+  extend self
+
+  def flatten(arr)
+    arr.flatten.compact
+  end
+end

generator/generator.cr

@@ -0,0 +1,20 @@
+require "./src/exercise_generator"
+require "./src/generators/*"
+
+if ARGV.empty?
+  STDERR.puts "Exercise name required!\n"
+  exit
+end
+
+exercise = ARGV[0]
+
+begin
+  klass = {{ExerciseGenerator.subclasses}}.find do |generator|
+    generator.to_s == "#{exercise.split('-').map(&.capitalize).join}Generator"
+  end
+
+  raise "Undefined Generator" unless klass
+  klass.generate
+rescue ex
+  STDERR.puts ex.message
+end

generator/shard.lock

@@ -0,0 +1,6 @@
+version: 1.0
+shards:
+  webmock:
+    github: manastech/webmock.cr
+    commit: c673f393a31eac2734c7599897357ef1f3f24011
+

generator/shard.yml

@@ -0,0 +1,9 @@
+name: generator
+version: 0.0.1
+
+development_dependencies:
+  webmock:
+    github: manastech/webmock.cr
+    branch: master
+
+license: MIT

src/generator/spec/exercise_generator_spec.cr → generator/spec/exercise_generator_spec.cr

@@ -1,6 +1,6 @@
 require "spec"
-require "../exercises/exercise_generator"
-require "../exercises/exercise_test_case"
+require "../src/exercise_generator"
+require "../src/exercise_test_case"
 
 class DummyGenerator < ExerciseGenerator
   def exercise_name

src/generator/spec/exercise_test_case_spec.cr → generator/spec/exercise_test_case_spec.cr

@@ -1,6 +1,6 @@
 require "spec"
 require "json"
-require "../exercises/exercise_test_case"
+require "../src/exercise_test_case"
 
 class DummyTestCase < ExerciseTestCase
   def workload; end

generator/spec/remote_data_file_spec.cr

@@ -0,0 +1,58 @@
+require "spec"
+require "file_utils"
+require "webmock"
+require "../src/remote_data_file"
+
+TEST_URL = [RemoteDataFile::BASE_URL, "test-exercise", RemoteDataFile::DATA_FILE].join("/")
+TEST_DIR = File.expand_path(File.join("..", "..", "cache", "test-exercise"), __FILE__)
+
+describe "RemoteDataFile" do
+  describe "#path" do
+    context "when successful" do
+      Spec.before_each do
+        clean_test_files
+        WebMock.reset
+      end
+
+      Spec.after_each do
+        clean_test_files
+      end
+
+      it "returns the response body if status is 200" do
+        WebMock.stub(:get, TEST_URL).to_return(status: 200, body: "file body")
+
+        remote_data_file = RemoteDataFile.new("test-exercise")
+
+        File.read(remote_data_file.path).should eq("file body")
+      end
+    end
+
+    context "when successful" do
+      it "raises a not found exception if status is 404" do
+        WebMock.stub(:get, TEST_URL).to_return(status: 404, body: "")
+
+        error_message = "A #{RemoteDataFile::DATA_FILE} doesn't exist for test-exercise in x-common. " +
+                        "Go make one!"
+
+        expect_raises(Exception, error_message) do
+          RemoteDataFile.new("test-exercise").path
+        end
+      end
+
+      it "raises a unexpected exception if status is other than 200 or 404" do
+        WebMock.stub(:get, TEST_URL).to_return(status: 500, body: "")
+
+
+        error_message = "Error while requesting the test-exercise data file from GitHub... " +
+                        "Status was 500"
+        expect_raises(Exception, error_message) do
+          RemoteDataFile.new("test-exercise").path
+        end
+      end
+    end
+  end
+end
+
+def clean_test_files
+  FileUtils.rm_rf(TEST_DIR)
+end

src/generator/exercises/exercise_generator.cr → generator/src/exercise_generator.cr

@@ -1,3 +1,5 @@
+require "./remote_data_file"
+
 require "ecr"
 require "json"
 
@@ -21,7 +23,7 @@ abstract class ExerciseGenerator
   abstract def test_cases
 
   private def root
-    File.expand_path(File.join("..", "..", "..", ".."), __FILE__)
+    File.expand_path(File.join("..", "..", ".."), __FILE__)
   end
 
   private def test_file
@@ -33,7 +35,13 @@ abstract class ExerciseGenerator
   end
 
   private def data
-    File.read(File.join(metadata_dir, "canonical-data.json"))
+    local_data_file = File.join(metadata_dir, "canonical-data.json")
+    if File.exists?(local_data_file)
+      File.read(local_data_file)
+    else
+      remote_data_file = RemoteDataFile.new(exercise_name)
+      File.read(remote_data_file.path)
+    end
   end
 
   ECR.def_to_s "#{__DIR__}/templates/example.tt"

src/generator/exercises/acronym.cr → generator/src/generators/acronym.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class AcronymGenerator < ExerciseGenerator
   def exercise_name

src/generator/exercises/binary.cr → generator/src/generators/binary.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class BinaryGenerator < ExerciseGenerator
   def exercise_name

src/generator/exercises/difference_of_squares.cr → generator/src/generators/difference_of_squares.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class DifferenceOfSquaresGenerator < ExerciseGenerator
   def exercise_name

generator/src/generators/flatten_array.cr

@@ -0,0 +1,43 @@
+require "../exercise_generator"
+require "../exercise_test_case"
+
+class FlattenArrayGenerator < ExerciseGenerator
+  def exercise_name
+    "flatten-array"
+  end
+
+  def test_cases
+    JSON.parse(data)["cases"].map do |test_case|
+      FlattenArrayTestCase.new(test_case)
+    end
+  end
+end
+
+class FlattenArrayTestCase < ExerciseTestCase
+  private getter description : JSON::Any
+  private getter input : JSON::Any
+  private getter expected : JSON::Any
+
+  def initialize(test_case)
+    @description = test_case["description"]
+    @input = test_case["input"]
+    @expected = fix_empty_array(test_case["expected"])
+  end
+
+  def workload
+    "FlattenArray.flatten(#{input}).should eq(#{expected})"
+  end
+
+  def test_name
+    description
+  end
+
+  def fix_empty_array(input)
+    if input.to_s.match(/\[\]/)
+      json = "[] of Nil".to_json
+      JSON.parse(json)
+    else
+      input
+    end
+  end
+end

src/generator/exercises/forth.cr → generator/src/generators/forth.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class ForthGenerator < ExerciseGenerator
   def exercise_name

src/generator/exercises/hello_world.cr → generator/src/generators/hello_world.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class HelloWorldGenerator < ExerciseGenerator
   def exercise_name

src/generator/exercises/pascals-triangle.cr → generator/src/generators/pascals-triangle.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class PascalsTriangleGenerator < ExerciseGenerator
   def exercise_name

src/generator/exercises/run_length_encoding.cr → generator/src/generators/run_length_encoding.cr

@@ -1,5 +1,5 @@
-require "./exercise_generator"
-require "./exercise_test_case"
+require "../exercise_generator"
+require "../exercise_test_case"
 
 class RunLengthEncodingGenerator < ExerciseGenerator
   def exercise_name