Starting to implement POGO for Gem::Specification and co

.gitignore

@@ -1,3 +1,5 @@
 build/
 .gradle/
 *.sw*
+.idea/
+*.iml

build.gradle

@@ -11,6 +11,12 @@ repositories {
 
 dependencies {
     compile "org.codehaus.groovy:groovy-all:2.4.0+"
+    compile 'joda-time:joda-time:2.6+'
+
+    compile 'com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:2.5.4'
+    compile 'com.fasterxml.jackson.core:jackson-annotations:2.5.4'
+    compile 'com.fasterxml.jackson.core:jackson-databind:2.5.4'
+
     codenarc "org.codenarc:CodeNarc:0.24"
     testCompile "org.spockframework:spock-core:1.0-groovy-2.4"
 }

src/main/groovy/com/github/jrubygradle/groovygem/Dependency.groovy

@@ -0,0 +1,16 @@
+package com.github.jrubygradle.groovygem
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import groovy.transform.TypeChecked
+import sun.org.mozilla.javascript.commonjs.module.Require
+
+/**
+ */
+@TypeChecked
+class Dependency {
+    @JsonProperty
+    String name
+
+    @JsonProperty
+    List<Requirement> requirements
+}

src/main/groovy/com/github/jrubygradle/groovygem/Gem.groovy

@@ -1,9 +1,75 @@
 package com.github.jrubygradle.groovygem
 
+import com.fasterxml.jackson.annotation.JsonProperty
+import com.fasterxml.jackson.databind.DeserializationFeature
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
+import groovy.transform.TypeChecked
+
 /**
- * Plain Old Groovy Object wrapping the data for a Gem
+ * Plain Old Groovy Object for an enumeration of metadata provided by a gem
  */
+@TypeChecked
 class Gem {
+    @JsonProperty
     String name
-    String version
+
+    @JsonProperty
+    Version version
+
+    @JsonProperty
+    String description
+
+    @JsonProperty
+    String platform
+
+    @JsonProperty
+    String email
+
+    @JsonProperty
+    String homepage
+
+    @JsonProperty
+    List<String> authors = []
+
+    @JsonProperty
+    List<String> files
+
+    @JsonProperty(value='test_files')
+    List<String> testFiles
+
+    @JsonProperty
+    List<String> executables
+
+    @JsonProperty(value='require_paths')
+    List<String> requirePaths
+
+    @JsonProperty
+    List<String> licenses
+
+    @JsonProperty(value='specification_version')
+    Integer specificationVersion
+
+    @JsonProperty(value='rubygems_version')
+    String rubygemsVersion
+
+    static Gem fromFile(Object metadata) {
+        File metadataFile
+        ObjectMapper mapper
+
+        if (metadata instanceof String) {
+            metadataFile = new File(metadata)
+        }
+        else if (metadata instanceof File) {
+            metadataFile = metadata as File
+        }
+
+        if (!(metadataFile?.exists())) {
+            return null
+        }
+
+        mapper = new ObjectMapper(new YAMLFactory())
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
+        return mapper.readValue(metadataFile, Gem.class)
+    }
 }

src/main/groovy/com/github/jrubygradle/groovygem/Requirement.groovy

@@ -0,0 +1,10 @@
+package com.github.jrubygradle.groovygem
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import groovy.transform.TypeChecked
+
+/**
+ */
+@TypeChecked
+class Requirement {
+}

src/main/groovy/com/github/jrubygradle/groovygem/Version.groovy

@@ -0,0 +1,10 @@
+package com.github.jrubygradle.groovygem
+
+import com.fasterxml.jackson.annotation.JsonProperty
+
+/**
+ */
+class Version {
+    @JsonProperty
+    String version
+}

src/test/groovy/com/github/jrubygradle/groovygem/GemSpec.groovy

@@ -1,6 +1,75 @@
 package com.github.jrubygradle.groovygem
 
+import com.fasterxml.jackson.databind.DeserializationConfig
+import com.fasterxml.jackson.databind.DeserializationFeature
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
 import spock.lang.*
 
 class GemSpec extends Specification {
+    final String FIXTURES_ROOT = new File(['src', 'test', 'resources'].join(File.separator)).absolutePath
+    final String METADATA_FIXTURE = [FIXTURES_ROOT, 'thor-0.19.1', 'metadata'].join(File.separator)
+
+    def "fromFile with an invalid/empty file should return null"() {
+        given:
+        Gem gem
+
+        when:
+        gem = Gem.fromFile(f)
+
+        then:
+        !(gem instanceof Gem)
+
+        where:
+        f                      | _
+        null                   | _
+        ''                     | _
+        new File('/tmp/spock') | _
+    }
+
+    def "fromFile with a valid file path should return a Gem"() {
+        given:
+        final String path = METADATA_FIXTURE
+
+        expect:
+        Gem.fromFile(path) instanceof Gem
+    }
+
+    def "fromFile with a valid File object should return a Gem"() {
+        given:
+        final File f = new File(METADATA_FIXTURE)
+
+        expect:
+        Gem.fromFile(f) instanceof Gem
+    }
+
+    def "a metadata file should parse into a Gem"() {
+        given:
+        Gem gem
+
+        when: "a metadata file is deserialized"
+        gem = Gem.fromFile(METADATA_FIXTURE)
+
+        then: "it should create an instance"
+        gem instanceof Gem
+
+        and: "its version should be correct"
+        gem.version.version == '0.19.1'
+
+        and: "its properties should equal what's in the YAML"
+        gem.getProperty(property) == value
+
+        where:
+        property               | value
+        'name'                 | 'thor'
+        'platform'             | 'ruby'
+        'email'                | 'ruby-thor@googlegroups.com'
+        'authors'              | ['Yehuda Katz', 'José Valim']
+        'executables'          | ['thor']
+        'licenses'             | ['MIT']
+        'homepage'             | 'http://whatisthor.com/'
+        'rubygemsVersion'      | '2.2.2'
+        'specificationVersion' | 4
+        'requirePaths'         | ['lib']
+    }
 }