iss #22: hedgehog.client.github.parseLinkHeader

app/hedgehog/StringUtils.scala

@@ -0,0 +1,12 @@
+package hedgehog
+
+/**
+ * Copyright (c) Nikita Kovaliov, maizy.ru, 2014
+ * See LICENSE.txt for details.
+ */
+object StringUtils {
+   implicit class StringImplicitConverters(val string: String) {
+       import scala.util.control.Exception._
+       def toIntOpt = catching(classOf[NumberFormatException]) opt string.toInt
+   }
+}

app/hedgehog/clients/github/package.scala

@@ -0,0 +1,42 @@
+package hedgehog.clients
+
+import scala.util.matching.Regex
+import com.netaporter.uri.Uri
+
+import hedgehog.StringUtils.StringImplicitConverters
+
+/**
+ * Copyright (c) Nikita Kovaliov, maizy.ru, 2014
+ * See LICENSE.txt for details.
+ */
+package object github {
+
+  case class HeaderLink(linkType: String, link: String, page: Option[Int], perPage: Option[Int])
+
+  private val headerSplitRegexp = """,\s""".r
+
+  def parseLinkHeader(header: String): Map[String, HeaderLink] =
+    //ex
+    //<https://api.github.com/organizations/12345/repos?per_page=100&page=2>; rel="next", <https://...>; rel="last"
+    (for {
+      rel <- headerSplitRegexp.split(header)
+      parsed <- parseRel(rel)
+    } yield parsed.linkType -> parsed).toMap
+
+  private val linkRegexp = new Regex("""<([^>]+)>;\s+rel="([^"]+)"""", "link", "linkType")
+
+  def parseRel(rel: String): Option[HeaderLink] =
+    //ex
+    //<https://api.github.com/organizations/12345/repos?per_page=100&page=2>; rel="next"
+    (linkRegexp findFirstMatchIn rel) map {
+      relMatch: Regex.Match => {
+        val link = relMatch.group("link")
+        val parsedLink = Uri.parse(link)
+        val linkType = relMatch.group("linkType")
+        def paramToOptInt(paramName: String): Option[Int] = {
+          parsedLink.query.param(paramName).last.toIntOpt
+        }
+        HeaderLink(linkType, link, paramToOptInt("page"), paramToOptInt("per_page"))
+      }
+    }
+}

build.sbt

@@ -7,7 +7,8 @@ libraryDependencies ++= Seq(
   //anorm,
   //cache,
   "org.scalatest" % "scalatest_2.10" % "2.1.7" % "test",
-  "com.github.nscala-time" %% "nscala-time" % "1.2.0"
+  "com.github.nscala-time" %% "nscala-time" % "1.2.0",
+  "com.netaporter" %% "scala-uri" % "0.4.2"
 )
 
 play.Project.playScalaSettings

test/clients/github/PackageSuite.scala

@@ -0,0 +1,56 @@
+package test
+
+import org.scalatest._
+
+import org.junit.runner.RunWith
+import org.scalatest.junit.JUnitRunner
+
+/**
+ * Copyright (c) Nikita Kovaliov, maizy.ru, 2014
+ * See LICENSE.txt for details.
+ */
+@RunWith(classOf[JUnitRunner])
+class PackageSuite extends FunSuite with Matchers {
+
+  import hedgehog.clients.github
+  import hedgehog.clients.github.HeaderLink
+
+  test("parseLinkHeader") {
+    val header =
+      """<https://api.github.com/organizations/12345/repos?per_page=100&page=2>; rel="next",
+        |<https://api.github.com/organizations/12345/repos?per_page=100&page=5>; rel="last"""".stripMargin
+
+    assert(
+      github.parseLinkHeader(header) === Map(
+        "next" -> HeaderLink(
+          linkType = "next",
+          link = "https://api.github.com/organizations/12345/repos?per_page=100&page=2",
+          page = Some(2),
+          perPage = Some(100)
+        ),
+        "last" -> HeaderLink(
+          linkType = "last",
+          link = "https://api.github.com/organizations/12345/repos?per_page=100&page=5",
+          page = Some(5),
+          perPage = Some(100)
+        )
+      )
+    )
+  }
+
+  test("parseLinkHeader for bad formatted values") {
+    assert(github.parseLinkHeader("") === Map())
+    assert(github.parseLinkHeader(", , , , ") === Map())
+    assert(
+      github.parseLinkHeader(
+        """<https://api.github.com/organizations/12345/repos?per_page=100&page=2>; rel="next", bubuub"""
+      ) === Map(
+        "next" -> HeaderLink(
+          linkType = "next",
+          link = "https://api.github.com/organizations/12345/repos?per_page=100&page=2",
+          page = Some(2),
+          perPage = Some(100)
+        )
+      ))
+  }
+}