add get tree api implementation

docs/src/main/tut/git_data.md

@@ -14,6 +14,7 @@ with Github4s, you can:
 - [Get a Commit](#get-a-commit)
 - [Create a Commit](#create-a-commit)
 - [Create a Blob](#create-a-blob)
+- [Get a Tree](#get-a-tree)
 - [Create a Tree](#create-a-tree)
 - [Create a Tag](#create-a-tag)
 
@@ -208,6 +209,28 @@ are just tools to navigate this tree and to manipulate it.
 
 In the following sections, we'll see how Github4s provides methods to wrap the Git API.
 
+
+### Get a Tree
+
+You can get a tree using `getTree`; it takes as arguments:
+
+- the repository coordinates (`owner` and `name` of the repository).
+- `sha`: the sha of the commit.
+- `recursive`: flag whether to get the tree recursively.
+
+```tut:silent
+val getCommit = Github(accessToken).gitData.getTree("47deg", "github4s", "d3b048c1f500ee5450e5d7b3d1921ed3e7645891",true)
+
+getCommit.exec[cats.Id, HttpResponse[String]]() match {
+  case Left(e) => println(s"Something went wrong: ${e.getMessage}")
+  case Right(r) => println(r.result)
+}
+```
+
+The `result` on the right is the corresponding [TreeResult][gitdata-scala].
+
+See [the API doc](https://developer.github.com/v3/git/trees/#get-a-tree) for full reference.
+
 ### Create a Tree
 
 The tree creation API will take nested entries as well. If both a tree and a nested entries modifying

github4s/shared/src/main/scala/github4s/GithubAPIs.scala

@@ -330,6 +330,14 @@ class GHGitData(accessToken: Option[String] = None)(implicit O: GitDataOps[GitHu
   ): GHIO[GHResponse[RefInfo]] =
     O.createBlob(owner, repo, content, encoding, accessToken)
 
+  def getTree(
+      owner: String,
+      repo: String,
+      sha: String,
+      recursive: Boolean
+  ): GHIO[GHResponse[TreeResult]] =
+    O.getTree(owner, repo, sha, recursive, accessToken)
+
   def createTree(
       owner: String,
       repo: String,

github4s/shared/src/main/scala/github4s/api/GitData.scala

@@ -191,6 +191,30 @@ class GitData[C, M[_]](
       headers,
       dropNullPrint(NewBlobRequest(content, encoding).asJson))
 
+  /**
+   * Get a Tree by sha
+   *
+   * @param accessToken to identify the authenticated user
+   * @param headers optional user headers to include in the request
+   * @param owner of the repo
+   * @param repo name of the repo
+   * @param sha the sha of the tree
+   * @param recursive flag whether to get the tree recursively
+   * @return a GHResponse with the Tree
+   */
+  def tree(
+      accessToken: Option[String] = None,
+      headers: Map[String, String] = Map(),
+      owner: String,
+      repo: String,
+      sha: String,
+      recursive: Boolean = false): M[GHResponse[TreeResult]] =
+    httpClient.get[TreeResult](
+      accessToken,
+      s"repos/$owner/$repo/git/trees/$sha",
+      headers,
+      (if (recursive) Map("recursive"->"1") else Map.empty))
+
   /**
    * Create a new Tree
    *

github4s/shared/src/main/scala/github4s/free/algebra/GitDataOps.scala

@@ -76,6 +76,14 @@ final case class CreateBlob(
     accessToken: Option[String] = None
 ) extends GitDataOp[GHResponse[RefInfo]]
 
+final case class GetTree(
+    owner: String,
+    repo: String,
+    sha: String,
+    recursive: Boolean,
+    accessToken: Option[String] = None
+) extends GitDataOp[GHResponse[TreeResult]]
+
 final case class CreateTree(
     owner: String,
     repo: String,
@@ -156,6 +164,15 @@ class GitDataOps[F[_]](implicit I: InjectK[GitDataOp, F]) {
   ): Free[F, GHResponse[RefInfo]] =
     Free.inject[GitDataOp, F](CreateBlob(owner, repo, content, encoding, accessToken))
 
+  def getTree(
+      owner: String,
+      repo: String,
+      sha: String,
+      recursive: Boolean,
+      accessToken: Option[String] = None
+  ): Free[F, GHResponse[TreeResult]] =
+    Free.inject[GitDataOp, F](GetTree(owner, repo, sha, recursive, accessToken))
+
   def createTree(
       owner: String,
       repo: String,

github4s/shared/src/main/scala/github4s/free/domain/GitData.scala

@@ -57,7 +57,8 @@ case class TreeDataBlob(path: String, mode: String, `type`: String, content: Str
 case class TreeResult(
     override val sha: String,
     override val url: String,
-    tree: List[TreeDataResult])
+    tree: List[TreeDataResult],
+    truncated: Option[Boolean] = None)
     extends RefInfo(sha, url)
 
 case class TreeDataResult(

github4s/shared/src/main/scala/github4s/free/interpreters/Interpreters.scala

@@ -281,6 +281,8 @@ class Interpreters[M[_], C](
             gitData.createBlob(accessToken, headers, owner, repo, content, encoding)
           case CreateTree(owner, repo, baseTree, treeDataList, accessToken) ⇒
             gitData.createTree(accessToken, headers, owner, repo, baseTree, treeDataList)
+          case GetTree(owner, repo, sha, recursive, accessToken) ⇒
+            gitData.tree(accessToken, headers, owner, repo, sha, recursive)
           case CreateTag(owner, repo, tag, message, objectSha, objectType, author, accessToken) ⇒
             gitData.createTag(
               accessToken,

github4s/shared/src/test/scala/github4s/integration/GHGitDataSpec.scala

@@ -19,7 +19,7 @@ package github4s.integration
 import cats.data.NonEmptyList
 import github4s.Github
 import github4s.Github._
-import github4s.free.domain.{Ref, RefCommit}
+import github4s.free.domain.{Ref, RefCommit, TreeResult}
 import github4s.implicits._
 import github4s.utils.BaseIntegrationSpec
 
@@ -73,4 +73,38 @@ trait GHGitDataSpec[T] extends BaseIntegrationSpec[T] {
 
     testFutureIsLeft(response)
   }
+
+  "GitData >> GetTree" should "return the file tree non-recursively" in {
+    val response =
+      Github(accessToken).gitData
+        .getTree(validRepoOwner, validRepoName, validCommitSha, recursive=false)
+        .execFuture[T](headerUserAgent)
+
+    testFutureIsRight[TreeResult](response, { r =>
+      r.statusCode shouldBe okStatusCode
+      r.result.tree.map(_.path) shouldBe List(".gitignore","build.sbt","project")
+      r.result.truncated shouldBe Some(false)
+    })
+  }
+
+  it should "return the file tree recursively" in {
+    val response =
+      Github(accessToken).gitData
+        .getTree(validRepoOwner, validRepoName, validCommitSha, recursive=true)
+        .execFuture[T](headerUserAgent)
+
+    testFutureIsRight[TreeResult](response, { r =>
+      r.statusCode shouldBe okStatusCode
+      r.result.tree.map(_.path) shouldBe List(".gitignore", "build.sbt", "project", "project/build.properties", "project/plugins.sbt")
+    })
+  }
+
+  it should "return an error when an invalid repository name is passed" in {
+    val response = Github(accessToken).gitData
+      .getTree(validRepoOwner, invalidRepoName, validCommitSha, recursive=false)
+      .execFuture[T](headerUserAgent)
+
+    testFutureIsLeft(response)
+  }
+
 }

github4s/shared/src/test/scala/github4s/unit/GHGitDataSpec.scala

@@ -135,6 +135,25 @@ class GHGitDataSpec extends BaseSpec {
     ghGitData.createBlob(validRepoOwner, validRepoName, validNote, encoding)
   }
 
+  "GHGitData.getTree" should "call to GitDataOps with the right parameters" in {
+
+    val response: Free[GitHub4s, GHResponse[TreeResult]] =
+      Free.pure(
+        Right(
+          GHResult(
+            TreeResult(validCommitSha, githubApiUrl, treeDataResult, truncated=Some(false)),
+            okStatusCode,
+            Map.empty)))
+
+    val gitDataOps = mock[GitDataOpsTest]
+    (gitDataOps.getTree _)
+      .expects(validRepoOwner, validRepoName, validCommitSha, false, sampleToken)
+      .returns(response)
+
+    val ghGitData = new GHGitData(sampleToken)(gitDataOps)
+    ghGitData.getTree(validRepoOwner, validRepoName, validCommitSha, recursive=false)
+  }
+
   "GHGitData.createTree" should "call to GitDataOps with the right parameters" in {
 
     val response: Free[GitHub4s, GHResponse[TreeResult]] =

github4s/shared/src/test/scala/github4s/unit/GitDataSpec.scala

@@ -182,6 +182,25 @@ class GitDataSpec extends BaseSpec {
       encoding)
   }
 
+  "GitData.getTree" should "call to httpClient.get with the right parameters" in {
+
+    val response: GHResponse[TreeResult] =
+      Right(
+        GHResult(
+          TreeResult(validCommitSha, githubApiUrl, treeDataResult, truncated=Some(false)),
+          okStatusCode,
+          Map.empty))
+    val httpClientMock = httpClientMockGet[TreeResult](
+      url = s"repos/$validRepoOwner/$validRepoName/git/trees/$validCommitSha",
+      response = response
+    )
+    val gitData = new GitData[String, Id] {
+      override val httpClient: HttpClient[String, Id] = httpClientMock
+    }
+
+    gitData.tree(sampleToken, headerUserAgent, validRepoOwner, validRepoName, validCommitSha, recursive=false)
+  }
+
   "GitData.createTree" should "call to httpClient.post with the right parameters" in {
 
     val response: GHResponse[TreeResult] =