ignore empty config files, closes #133

CHANGELOG.markdown

@@ -2,6 +2,7 @@
 
 ## unreleased
 
+* Ignore empty config files [#133](https://github.com/toy/image_optim/issues/133) [@toy](https://github.com/toy)
 * Use `FileUtils.move` in `ImagePath#replace` to rename file instead of copying on same device [#134](https://github.com/toy/image_optim/issues/134) [@toy](https://github.com/toy)
 * Make `:allow_lossy` an individual option for workers that can use it, so it will be in the list of worker options [#130](https://github.com/toy/image_optim/issues/130) [@toy](https://github.com/toy)
 * Use first 8 characters of sha1 hex for jpegrescan version [#131](https://github.com/toy/image_optim/issues/131) [@toy](https://github.com/toy)

lib/image_optim/config.rb

@@ -22,15 +22,16 @@ class Config
 
     class << self
       # Read options at path: expand path (warn on failure), return {} if file
-      # does not exist, read yaml, check if it is a Hash, deep symbolise keys
+      # does not exist or is empty, read yaml, check if it is a Hash, deep
+      # symbolise keys
       def read_options(path)
         begin
           full_path = File.expand_path(path)
         rescue ArgumentError => e
           warn "Can't expand path #{path}: #{e}"
           return {}
         end
-        return {} unless File.file?(full_path)
+        return {} unless File.size?(full_path)
         config = YAML.load_file(full_path)
         unless config.is_a?(Hash)
           fail "expected hash, got #{config.inspect}"

spec/image_optim/config_spec.rb

@@ -159,16 +159,16 @@ def image_formats
         expect(IOConfig).to receive(:warn)
         expect(File).to receive(:expand_path).
           with(path).and_raise(ArgumentError)
-        expect(File).not_to receive(:file?)
+        expect(File).not_to receive(:size?)
 
         expect(IOConfig.read_options(path)).to eq({})
       end
 
-      it 'returns empty hash if path is not a file' do
+      it 'returns empty hash if path is not a file or is an empty file' do
         expect(IOConfig).not_to receive(:warn)
         expect(File).to receive(:expand_path).
           with(path).and_return(full_path)
-        expect(File).to receive(:file?).
+        expect(File).to receive(:size?).
           with(full_path).and_return(false)
 
         expect(IOConfig.read_options(path)).to eq({})
@@ -181,7 +181,7 @@ def image_formats
         expect(IOConfig).not_to receive(:warn)
         expect(File).to receive(:expand_path).
           with(path).and_return(full_path)
-        expect(File).to receive(:file?).
+        expect(File).to receive(:size?).
           with(full_path).and_return(true)
         expect(YAML).to receive(:load_file).
           with(full_path).and_return(stringified)
@@ -193,7 +193,7 @@ def image_formats
         expect(IOConfig).to receive(:warn)
         expect(File).to receive(:expand_path).
           with(path).and_return(full_path)
-        expect(File).to receive(:file?).
+        expect(File).to receive(:size?).
           with(full_path).and_return(true)
         expect(YAML).to receive(:load_file).
           with(full_path).and_return([:config])
@@ -205,7 +205,7 @@ def image_formats
         expect(IOConfig).to receive(:warn)
         expect(File).to receive(:expand_path).
           with(path).and_return(full_path)
-        expect(File).to receive(:file?).
+        expect(File).to receive(:size?).
           with(full_path).and_return(true)
         expect(YAML).to receive(:load_file).
           with(full_path).and_raise