Add library.properties parsing

Author: ianfixes

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Add `__AVR__` to defines when compiling
 - `arduino_ci_remote.rb` CLI switch `--skip-examples-compilation`
 - `CppLibrary.header_files` to find header files
+- `LibraryProperties` to read metadata from Arduino libraries
 
 ### Changed
 - Move repository from https://github.com/ianfixes/arduino_ci to https://github.com/Arduino-CI/arduino_ci

lib/arduino_ci.rb

@@ -2,6 +2,7 @@
 require "arduino_ci/arduino_installation"
 require "arduino_ci/cpp_library"
 require "arduino_ci/ci_config"
+require "arduino_ci/library_properties"
 
 # ArduinoCI contains classes for automated testing of Arduino code on the command line
 # @author Ian Katz <[email protected]>

lib/arduino_ci/library_properties.rb

@@ -0,0 +1,86 @@
+module ArduinoCI
+
+  # Information about an Arduino library package, as specified by the library.properties file
+  #
+  # See https://arduino.github.io/arduino-cli/library-specification/#libraryproperties-file-format
+  class LibraryProperties
+
+    # @return [Hash] The properties file parsed as a hash
+    attr_reader :fields
+
+    # @param path [Pathname] The path to the library.properties file
+    def initialize(path)
+      @fields = {}
+      File.foreach(path) do |line|
+        parts = line.split("=", 2)
+        @fields[parts[0]] = parts[1].chomp unless parts.empty?
+      end
+    end
+
+    # Enable a shortcut syntax for library property accessors, in the style of `attr_accessor` metaprogramming.
+    # This is used to create a named field pointing to a specific property in the file, optionally applying
+    # a specific formatting function.
+    #
+    #  The formatting function MUST be a static method on this class.  This is a limitation caused by the desire
+    #  to both (1) expose the formatters outside this class, and (2) use them for metaprogramming without the
+    #  having to name the entire function.  field_reader is a static method, so if not for the fact that
+    #  `self.class.methods.include? formatter` fails to work for class methods in this context (unlike
+    #  `self.methods.include?`, which properly finds instance methods), I would allow either one and just
+    #  conditionally `define_method` the proper definition
+    #
+    # @param name [String] What the accessor will be called
+    # @param field_num [Integer] The name of the key of the property
+    # @param formatter [Symbol] The symbol for the formatting function to apply to the field (optional)
+    # @return [void]
+    # @macro [attach] field_reader
+    #   @!attribute [r] $1
+    #   @return property $2 of the library.properties file, formatted with the function {$3}
+    def self.field_reader(name, formatter = nil)
+      key = name.to_s
+      if formatter.nil?
+        define_method(name) { @fields[key] }
+      else
+        define_method(name) { @fields.key?(key) ? self.class.send(formatter.to_sym, @fields[key]) : nil }
+      end
+    end
+
+    # Parse a value as a comma-separated array
+    # @param input [String]
+    # @return [Array<String>] The individual values
+    def self._csv(input)
+      input.split(",").map(&:strip)
+    end
+
+    # Parse a value as a boolean
+    # @param input [String]
+    # @return [Array<String>] The individual values
+    def self._bool(input)
+      input == "true"  # no indication given in the docs that anything but lowercase "true" indicates boolean true.
+    end
+
+    field_reader :name
+    field_reader :version
+    field_reader :author, :_csv
+    field_reader :maintainer
+    field_reader :sentence
+    field_reader :paragraph
+    field_reader :category
+    field_reader :url
+    field_reader :architectures, :_csv
+    field_reader :depends, :_csv
+    field_reader :dot_a_linkage, :_bool
+    field_reader :includes, :_csv
+    field_reader :precompiled, :_bool
+    field_reader :ldflags, :_csv
+
+    # The value of sentence always will be prepended, so you should start by writing the second sentence here
+    #
+    # (according to the docs)
+    # @return [String] the sentence and paragraph together
+    def full_paragraph
+      [sentence, paragraph].join(" ")
+    end
+
+  end
+
+end

spec/library_properties_spec.rb

@@ -0,0 +1,45 @@
+require "spec_helper"
+
+RSpec.describe ArduinoCI::LibraryProperties do
+
+  context "property extraction" do
+    library_properties = ArduinoCI::LibraryProperties.new(Pathname.new(__dir__) + "properties/example.library.properties")
+
+    expected = {
+      string: {
+        name: "WebServer",
+        version: "1.0.0",
+        maintainer: "Cristian Maglie <[email protected]>",
+        sentence: "A library that makes coding a Webserver a breeze.",
+        paragraph: "Supports HTTP1.1 and you can do GET and POST.",
+        category: "Communication",
+        url: "http://example.com/",
+      },
+
+      bool: {
+        precompiled: true
+      },
+
+      csv: {
+        author: ["Cristian Maglie <[email protected]>", "Pippo Pluto <[email protected]>"],
+        architectures: ["avr"],
+        includes: ["WebServer.h"],
+        depends: ["ArduinoHttpClient"],
+      },
+    }.freeze
+
+    expected.each do |atype, values|
+      values.each do |meth, val|
+        it "reads #{atype} field #{meth}" do
+          expect(library_properties.send(meth)).to eq(val)
+        end
+      end
+    end
+
+    it "doesn't crash on nonexistent fields" do
+      expect(library_properties.dot_a_linkage).to be(nil)
+    end
+  end
+
+
+end

spec/properties/example.library.properties

@@ -0,0 +1,12 @@
+name=WebServer
+version=1.0.0
+author=Cristian Maglie <[email protected]>, Pippo Pluto <[email protected]>
+maintainer=Cristian Maglie <[email protected]>
+sentence=A library that makes coding a Webserver a breeze.
+paragraph=Supports HTTP1.1 and you can do GET and POST.
+category=Communication
+url=http://example.com/
+architectures=avr
+includes=WebServer.h
+depends=ArduinoHttpClient
+precompiled=true