Added status attribute to PngCheck::EmptyPngError, PngCheck::CorruptP…

…ngError

README.adoc

@@ -113,6 +113,8 @@ Where:
 * `valid` is `true` if the buffer is correct image
 * otherwise an exception is raised. Possible exception types are `PngCheck::EmptyPngError`, `PngCheck::CorruptPngError`
 
+Both exception classes have additional status attribute that is set to one of STATUX_XXX codes described above. We believe that
+exceptions with STATUS_WARNING can be ignored in the majority of applications.
 
 ==== Pre-validation with libpng-ruby
 

lib/pngcheck.rb

@@ -14,14 +14,19 @@ module PngCheck
   EMPTY_IMAGE = "Image is empty"
 
   class CorruptPngError < StandardError
-    def initialize(msg, status = STATUS_MAJOR_ERROR)
+    def initialize(msg, sts = STATUS_MAJOR_ERROR)
       super(msg)
+      @status = sts
+    end
+
+    def status
+      @status
     end
   end
 
-  class EmptyPngError < StandardError
-    def initialize(msg = EMPTY_IMAGE, status = STATUS_CRITICAL_ERROR)
-      super(msg)
+  class EmptyPngError < CorruptPngError
+    def initialize(msg = EMPTY_IMAGE)
+      super(msg, STATUS_CRITICAL_ERROR)
     end
   end
 

lib/pngcheck/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module PngCheck
-  VERSION = "0.2.8"
+  VERSION = "0.3.0"
 end

spec/pngcheck_spec.rb

@@ -16,10 +16,10 @@
     #    puts "--> info: #{info}\n"
   end
 
-  it "analyzes MacOS screenshot" do
+  it "sets STATUS_WARNING for MacOS screenshot" do
     status, info = PngCheck.analyze_file("spec/examples/macos-screenshot.png")
     expect(status).to eql PngCheck::STATUS_WARNING
-    expect(info).to include "illegal (unless recently approved) unknown, public chunk"
+    expect(info).to include "illegal (unless recently approved) unknown"
     #    puts "--> info: #{info}\n"
   end
 
@@ -45,21 +45,24 @@
     expect(PngCheck.check_file("spec/examples/correct2.png")).to eql true
   end
   it "raises an exception on corrupt file check" do
-    expect do
-      PngCheck.check_file("spec/examples/corrupt.png")
-    end.to raise_error(PngCheck::CorruptPngError)
+    PngCheck.check_file("spec/examples/corrupt.png")
+    expect(false).to be true
+  rescue PngCheck::CorruptPngError => e
+    expect(e.status).to eql PngCheck::STATUS_MAJOR_ERROR
   end
 
   it "raises an exception on empty file check" do
-    expect do
-      PngCheck.check_file("spec/examples/empty.png")
-    end.to raise_error(PngCheck::EmptyPngError)
+    PngCheck.check_file("spec/examples/empty.png")
+    expect(false).to be true
+  rescue PngCheck::EmptyPngError => e
+    expect(e.status).to eql PngCheck::STATUS_CRITICAL_ERROR
   end
 
   it "raises an exception on missing file check" do
-    expect do
-      PngCheck.check_file("spec/examples/nofile.png")
-    end.to raise_error(PngCheck::CorruptPngError)
+    PngCheck.check_file("spec/examples/nofile.png")
+    expect(false).to be true
+  rescue PngCheck::CorruptPngError => e
+    expect(e.status).to eql PngCheck::STATUS_CRITICAL_ERROR
   end
 
   it "analyzes correct buffer" do
@@ -100,40 +103,61 @@
     expect(PngCheck.check_buffer(encoded)).to eql true
   end
 
+  it "sets STATUS_WARNING for a buffer generated from MacOS screenshot" do
+    encoded = File.binread("spec/examples/macos-screenshot.png")
+    status, info = PngCheck.analyze_buffer(encoded)
+    expect(status).to eql PngCheck::STATUS_WARNING
+    expect(info).to include "illegal (unless recently approved) unknown"
+  end
+
   it "raises an exception on corrupt buffer check" do
     encoded = File.binread("spec/examples/corrupt.png")
-    expect do
-      PngCheck.check_buffer(encoded)
-    end.to raise_error(PngCheck::CorruptPngError)
+    PngCheck.check_buffer(encoded)
+    expect(false).to be true
+  rescue PngCheck::CorruptPngError => e
+    expect(e.status).to eql PngCheck::STATUS_MAJOR_ERROR
   end
 
   it "raises an exception on trash buffer check" do
     encoded = "[this is just a string]"
-    expect do
-      PngCheck.check_buffer(encoded)
-    end.to raise_error(PngCheck::CorruptPngError)
+    PngCheck.check_buffer(encoded)
+    expect(false).to be true
+  rescue PngCheck::CorruptPngError => e
+    expect(e.status).to eql PngCheck::STATUS_CRITICAL_ERROR
   end
 
   it "raises an exception on empty buffer check" do
     encoded = ""
-    expect do
-      PngCheck.check_buffer(encoded)
-    end.to raise_error(PngCheck::EmptyPngError)
-  end
-
-  require "png"
-
-  it "can be used with libpng-ruby" do
-    encoded = File.binread("spec/examples/correct.png")
-    begin
-      expect(PngCheck.check_buffer(encoded)).to eql true
-      dec = PNG::Decoder.new
-      raw = dec << encoded
-    rescue PngCheck::CorruptPngError => e
-      puts "Exception #{e.message}"
+    PngCheck.check_buffer(encoded)
+    expect(false).to be true
+  rescue PngCheck::EmptyPngError => e
+    expect(e.status).to eql PngCheck::STATUS_CRITICAL_ERROR
+  end
+
+  it "raises an exception on macos screenshot with status equal to STATUS_WARNING" do
+    encoded = File.binread("spec/examples/macos-screenshot.png")
+    PngCheck.check_buffer(encoded)
+    expect(false).to be true
+  rescue PngCheck::CorruptPngError => e
+    expect(e.status).to eql PngCheck::STATUS_WARNING
+  end
+
+  begin
+    require "png"
+    it "can be used with libpng-ruby" do
+      encoded = File.binread("spec/examples/correct.png")
+      begin
+        expect(PngCheck.check_buffer(encoded)).to eql true
+        dec = PNG::Decoder.new
+        raw = dec << encoded
+      rescue PngCheck::CorruptPngError => e
+        puts "Exception #{e.message}"
+      end
+      f = "aaaaaaaaa"
+      expect(raw.unpack(f)).to start_with
+      "\xF4\xD1\r\xF4\xD1\r\xF4\xD1\r\xF4".unpack(f)
     end
-    f = "aaaaaaaaa"
-    expect(raw.unpack(f)).to start_with
-    "\xF4\xD1\r\xF4\xD1\r\xF4\xD1\r\xF4".unpack(f)
+  rescue LoadError => e
+    puts "Failed to load libpng-ruby, skipping compatibility test"
   end
 end