[WIP] Add specs for spec output

spec/std/spec/output_spec.cr

@@ -0,0 +1,189 @@
+require "spec"
+
+private SAMPLE_SPEC_FILE = "foo_spec.cr"
+
+class DummyRootContext < Spec::RootContext
+  @io = String::Builder.new
+
+  property lines = {} of {String, Int32} => String
+
+  delegate puts, print, to: @io
+
+  def output
+    @io.to_s
+  end
+
+  def report(result)
+    # Spec.formatters.each(&.report(result))
+
+    @results[result.kind] << result
+  end
+
+  private def read_line(file, line)
+    lines[{file, line}]?
+  end
+end
+
+class DummyFormatter < Spec::Formatter
+  getter results = [] of Spec::Result
+
+  def report(result)
+    @results << result
+  end
+
+  def finish
+    puts
+  end
+end
+
+private class SpecEnvironment
+  getter root = DummyRootContext.new
+  getter formatters
+
+  def initialize(@formatters = [DummyFormatter.new])
+    @contexts_stack = [@root] of Spec::Context
+  end
+
+  def self.run(elapsed_time = 42.milliseconds, use_color = false)
+    instance = new
+
+    old_color = Spec.use_colors?
+    begin
+      Spec.use_colors = use_color
+
+      yield instance
+
+      instance.@root.print_results(elapsed_time)
+    ensure
+      Spec.use_colors = old_color
+    end
+
+    instance.@root.output
+  end
+
+  def describe(description, file, line, &block)
+    describe = Spec::NestedContext.new(description, file, line, @contexts_stack.last)
+    @contexts_stack.push describe
+    @formatters.each(&.push(describe))
+    block.call
+    @formatters.each(&.pop)
+    @contexts_stack.pop
+  end
+
+  def it(description = "assert", file = __FILE__, line = __LINE__, end_line = __END_LINE__, &block)
+    @formatters.each(&.before_example(description))
+
+    start = Time.monotonic
+    begin
+      # Spec.run_before_each_hooks
+      block.call
+      report(:success, description, file, line, Time.monotonic - start)
+    rescue ex : Spec::AssertionFailed
+      report(:fail, description, file, line, Time.monotonic - start, ex)
+      # Spec.abort! if Spec.fail_fast?
+    rescue ex
+      report(:error, description, file, line, Time.monotonic - start, ex)
+      # Spec.abort! if Spec.fail_fast?
+    ensure
+      # Spec.run_after_each_hooks
+    end
+  end
+
+  private def report(kind, full_description, file, line, elapsed = nil, ex = nil)
+    result = Spec::Result.new(kind, full_description, file, line, elapsed, ex)
+    @contexts_stack.last.report(result)
+  end
+
+  def pending(description = "assert", file = __FILE__, line = __LINE__, end_line = __END_LINE__, &block)
+    @formatters.each(&.before_example(description))
+
+    @root.report(:pending, description, file, line)
+  end
+end
+
+describe "spec output" do
+  it "empty example" do
+    output = SpecEnvironment.run do |env|
+      env.describe "foo test", SAMPLE_SPEC_FILE, 3 do
+        env.it "passes a test", SAMPLE_SPEC_FILE, 4, 5 { }
+      end
+
+      # env.formatters.first.as(DummyFormatter).results.map(&.kind).should eq [:success]
+    end
+
+    output.should eq <<-'RESULT'
+
+      Finished in 42.0 milliseconds
+      1 examples, 0 failures, 0 errors, 0 pending
+
+      RESULT
+  end
+
+  it "failing example" do
+    output = SpecEnvironment.run do |env|
+      env.root.lines[{SAMPLE_SPEC_FILE, 5}] = "3.should eq 4"
+      env.describe "foo test", SAMPLE_SPEC_FILE, 3 do
+        env.it "passes a test", SAMPLE_SPEC_FILE, 4, 6 do
+          3.should eq(4), SAMPLE_SPEC_FILE, 5
+        end
+      end
+
+      # env.formatters.first.as(DummyFormatter).results.map(&.kind).should eq [:success]
+    end
+
+    output.should eq <<-'RESULT'
+
+      Failures:
+
+        1) foo test passes a test
+           Failure/Error: 3.should eq 4
+
+             Expected: 4
+                  got: 3
+
+           # foo_spec.cr:5
+
+      Finished in 42.0 milliseconds
+      1 examples, 1 failures, 0 errors, 0 pending
+
+      Failed examples:
+
+      crystal spec foo_spec.cr:4 # foo test passes a test
+
+      RESULT
+  end
+
+  it "raising example" do
+    output = SpecEnvironment.run do |env|
+      env.describe "foo test", SAMPLE_SPEC_FILE, 3 do
+        env.it "passes a test", SAMPLE_SPEC_FILE, 4, 5 do
+          raise "unexpected exception"
+        end
+      end
+
+      # env.formatters.first.as(DummyFormatter).results.map(&.kind).should eq [:success]
+    end
+
+    intro, search, rest = output.partition "unexpected exception"
+
+    (intro + search).should eq <<-'RESULT'
+
+      Failures:
+
+        1) foo test passes a test
+
+             unexpected exception
+      RESULT
+
+    callstack, search, outro = rest.partition("Finished in 42.0 milliseconds")
+    (search + outro).should eq <<-'RESULT'
+      Finished in 42.0 milliseconds
+      1 examples, 0 failures, 1 errors, 0 pending
+
+      Failed examples:
+
+      crystal spec foo_spec.cr:4 # foo test passes a test
+
+      RESULT
+  end
+end

src/spec/context.cr

@@ -75,7 +75,7 @@ module Spec
             puts "#{(i + 1).to_s.rjust(3, ' ')}) #{fail.description}"
 
             if ex.is_a?(AssertionFailed)
-              source_line = Spec.read_line(ex.file, ex.line)
+              source_line = read_line(ex.file, ex.line)
               if source_line
                 puts Spec.color("     Failure/Error: #{source_line.strip}", :error)
               end
@@ -143,6 +143,10 @@ module Spec
       end
     end
 
+    private def read_line(file, line)
+      Spec.read_line(file, line)
+    end
+
     @@instance = RootContext.new
     @@contexts_stack = [@@instance] of Context