Basically done JSON formatter

src/spectator/error_result.cr

@@ -20,28 +20,9 @@ module Spectator
       io << "error"
     end
 
-    # Adds the common JSON fields for all result types
-    # and fields specific to errored results.
-    private def add_json_fields(json : ::JSON::Builder)
-      super
-      json.field("exceptions") do
-        exception = error
-        json.array do
-          while exception
-            error_to_json(exception, json) if exception
-            exception = error.cause
-          end
-        end
-      end
-    end
-
-    # Adds a single exception to a JSON builder.
-    private def error_to_json(error : Exception, json : ::JSON::Builder)
-      json.object do
-        json.field("type", error.class.to_s)
-        json.field("message", error.message)
-        json.field("backtrace", error.backtrace)
-      end
+    # String used for the JSON status field.
+    private def json_status
+      "error"
     end
   end
 end

src/spectator/example.cr

@@ -165,8 +165,14 @@ module Spectator
 
     # Creates the JSON representation of the example,
     # which is just its name.
-    def to_json(json : ::JSON::Builder)
-      json.string(to_s)
+    def to_json(json : JSON::Builder)
+      json.object do
+        json.field("description", name? || "<anonymous>")
+        json.field("full_description", to_s)
+        json.field("file_path", location.path)
+        json.field("line_number", location.line)
+        @result.to_json(json) if @finished
+      end
     end
 
     # Creates a procsy from this example and the provided block.

src/spectator/expectation.cr

@@ -1,3 +1,4 @@
+require "json"
 require "./expression"
 require "./location"
 
@@ -53,7 +54,7 @@ module Spectator
     end
 
     # Creates the JSON representation of the expectation.
-    def to_json(json : ::JSON::Builder)
+    def to_json(json : JSON::Builder)
       json.object do
         json.field("location") { @location.to_json(json) }
         json.field("satisfied", satisfied?)
@@ -64,7 +65,7 @@ module Spectator
     end
 
     # Adds failure information to a JSON structure.
-    private def failed_to_json(failed : Matchers::FailedMatchData, json : ::JSON::Builder)
+    private def failed_to_json(failed : Matchers::FailedMatchData, json : JSON::Builder)
       json.field("failure", failed.failure_message)
       json.field("values") do
         json.object do

src/spectator/fail_result.cr

@@ -1,3 +1,4 @@
+require "json"
 require "./result"
 
 module Spectator
@@ -40,10 +41,23 @@ module Spectator
       io << "fail"
     end
 
-    # Adds all of the JSON fields for finished results and failed results.
-    private def add_json_fields(json : ::JSON::Builder)
+    # Creates a JSON object from the result information.
+    def to_json(json : JSON::Builder)
       super
-      json.field("error", error.message)
+      json.field("status", json_status)
+      json.field("exception") do
+        json.object do
+          json.field("class", @error.class.name)
+          json.field("message", @error.message)
+          json.field("backtrace", @error.backtrace)
+        end
+      end
+    end
+
+    # String used for the JSON status field.
+    # Necessary for the error result to override the status, but nothing else from `#to_json`.
+    private def json_status
+      "failed"
     end
   end
 end

src/spectator/formatting/json_formatter.cr

@@ -1,6 +1,141 @@
+require "json"
 require "./formatter"
 
 module Spectator::Formatting
+  # Produces a JSON document with results of the test suite.
   class JSONFormatter < Formatter
+    # Creates the formatter.
+    # By default, output is sent to STDOUT.
+    def initialize(io = STDOUT)
+      @json = JSON::Builder.new(io)
+    end
+
+    # Begins the JSON document output.
+    def start(_notification)
+      @json.start_document
+      @json.start_object
+      @json.field("version", Spectator::VERSION)
+
+      # Start examples array.
+      @json.string("examples")
+      @json.start_array
+    end
+
+    # Begins an example object and adds common fields known before running the example.
+    def example_started(notification)
+      example = notification.example
+
+      @json.start_object
+      @json.field("description", example.name? || "<anonymous>")
+      @json.field("full_description", example)
+      @json.field("file_path", example.location.path)
+      @json.field("line_number", example.location.line)
+    end
+
+    # Adds fields to the example object for all result types known after the example completes.
+    def example_finished(notification)
+      example = notification.example
+      result = example.result
+
+      @json.field("run_time", result.elapsed.total_seconds)
+      @json.field("expectations") do
+        @json.array do
+          result.expectations.each(&.to_json(@json))
+        end
+      end
+    end
+
+    # Adds success-specific fields to an example object and closes it.
+    def example_passed(_notification)
+      @json.field("status", "passed")
+      @json.end_object # End example object.
+    end
+
+    # Adds pending-specific fields to an example object and closes it.
+    def example_pending(_notification)
+      @json.field("status", "pending")
+      @json.field("pending_message", "Not implemented") # TODO: Fetch pending message from result.
+      @json.end_object # End example object.
+    end
+
+    # Adds failure-specific fields to an example object and closes it.
+    def example_failed(notification)
+      example = notification.example
+      result = example.result
+
+      @json.field("status", "failed")
+      build_exception_object(result.error) if result.responds_to?(:error)
+      @json.end_object # End example object.
+    end
+
+    # Adds error-specific fields to an example object and closes it.
+    def example_error(notification)
+      example = notification.example
+      result = example.result
+
+      @json.field("status", "error")
+      build_exception_object(result.error) if result.responds_to?(:error)
+      @json.end_object # End example object.
+    end
+
+    # Adds an exception field and object to the JSON document.
+    private def build_exception_object(error)
+      @json.field("exception") do
+        @json.object do
+          @json.field("class", error.class.name)
+          @json.field("message", error.message)
+          @json.field("backtrace", error.backtrace)
+        end
+      end
+    end
+
+    # Marks the end of the examples array.
+    def stop
+      @json.end_array # Close examples array.
+    end
+
+    # Adds the profiling information to the document.
+    def dump_profile(notification)
+      profile = notification.profile
+
+      @json.field("profile") do
+        @json.object do
+          @json.field("examples") do
+            @json.array do
+              profile.each(&.to_json(@json))
+            end
+          end
+
+          @json.field("slowest", profile.max_of(&.result.elapsed).total_seconds)
+          @json.field("total", profile.time.total_seconds)
+          @json.field("percentage", profile.percentage)
+        end
+      end
+    end
+
+    # Adds the summary object to the document.
+    def dump_summary(notification)
+      report = notification.report
+
+      @json.field("summary") do
+        @json.object do
+          @json.field("duration", report.runtime.total_seconds)
+          @json.field("example_count", report.counts.total)
+          @json.field("failure_count", report.counts.fail)
+          @json.field("error_count", report.counts.error)
+          @json.field("pending_count", report.counts.pending)
+        end
+      end
+
+      totals = Components::Totals.new(report.counts)
+      @json.field("summary_line", totals.to_s)
+    end
+
+    # Ends the JSON document and flushes output.
+    def close
+      @json.end_object
+      @json.end_document
+      @json.flush
+    end
   end
 end

src/spectator/pass_result.cr

@@ -27,5 +27,11 @@ module Spectator
     def to_s(io)
       io << "pass"
     end
+
+    # Creates a JSON object from the result information.
+    def to_json(json : JSON::Builder)
+      super
+      json.field("status", "passed")
+    end
   end
 end

src/spectator/pending_result.cr

@@ -35,5 +35,12 @@ module Spectator
     def to_s(io)
       io << "pending"
     end
+
+    # Creates a JSON object from the result information.
+    def to_json(json : JSON::Builder)
+      super
+      json.field("status", "pending")
+      json.field("pending_message", "Not implemented") # TODO: Provide pending message.
+    end
   end
 end

src/spectator/result.cr

@@ -1,3 +1,6 @@
+require "json"
+require "./expectation"
+
 module Spectator
   # Base class that represents the outcome of running an example.
   # Sub-classes contain additional information specific to the type of result.
@@ -29,19 +32,13 @@ module Spectator
     end
 
     # Creates a JSON object from the result information.
-    def to_json(json : ::JSON::Builder, example)
-      json.object do
-        add_json_fields(json, example)
-      end
-    end
-
-    # Adds the common fields for a result to a JSON builder.
-    private def add_json_fields(json : ::JSON::Builder, example)
-      json.field("name", example)
-      json.field("location", example.location)
-      json.field("result", to_s)
-      json.field("time", elapsed.total_seconds)
-      json.field("expectations", expectations)
+    def to_json(json : JSON::Builder)
+      json.field("run_time", @elapsed.total_seconds)
+      json.field("expectations") do
+        json.array do
+          @expectations.each(&.to_json(json))
+        end
+      end
     end
   end
 end