add origin function

2 files changed, 49 insertions, 1 deletions

diff --git a/src/gleam/uri.gleam b/src/gleam/uri.gleam
index f92f91a..9224adf 100644
--- a/src/gleam/uri.gleam
+++ b/src/gleam/uri.gleam
@@ -9,7 +9,7 @@
 
 import gleam/list
 import gleam/result
-import gleam/option.{Option}
+import gleam/option.{Option, Some, None}
 import gleam/string
 import gleam/dynamic.{Dynamic}
 import gleam/map.{Map}
@@ -164,3 +164,21 @@ pub fn to_string(uri: Uri) -> String {
   |> dynamic.string
   |> result.unwrap("")
 }
+
+/// Fetch the origin of a url
+///
+/// Return the origin of a url as defined in
+/// https://tools.ietf.org/html/rfc6454
+///
+/// The supported url schemes are `http` and `https`
+/// Urls without a scheme will return Error
+pub fn origin(uri: Uri) -> Result(String, Nil) {
+  let Uri(scheme: scheme, host: host, port: port, ..) = uri
+  case scheme {
+    Some("https") | Some("http") -> {
+      let origin = Uri(scheme, None, host, port, "", None, None)
+      Ok(to_string(origin))
+    }
+    _ -> Error(Nil)
+  }
+}
diff --git a/test/gleam/uri_test.gleam b/test/gleam/uri_test.gleam
index 49b4c02..9f102e0 100644
--- a/test/gleam/uri_test.gleam
+++ b/test/gleam/uri_test.gleam
@@ -101,3 +101,33 @@ pub fn parse_segments_test() {
   should.equal(uri.path_segments("../bar"), ["bar"])
   should.equal(uri.path_segments("/foo/../bar"), ["bar"])
 }
+
+pub fn origin_test() {
+  let Ok(parsed) = uri.parse("http://example.test/path?foo#bar")
+  uri.origin(parsed)
+  |> should.equal(Ok("http://example.test"))
+
+  let Ok(parsed) = uri.parse("http://example.test:8080")
+  uri.origin(parsed)
+  |> should.equal(Ok("http://example.test:8080"))
+
+  let Ok(parsed) = uri.parse("https://example.test")
+  uri.origin(parsed)
+  |> should.equal(Ok("https://example.test"))
+
+  let Ok(parsed) = uri.parse("http:///path")
+  uri.origin(parsed)
+  |> should.equal(Ok("http://"))
+
+  let Ok(parsed) = uri.parse("http://")
+  uri.origin(parsed)
+  |> should.equal(Ok("http://"))
+
+  let Ok(parsed) = uri.parse("/path")
+  uri.origin(parsed)
+  |> should.equal(Error(Nil))
+
+  let Ok(parsed) = uri.parse("file:///dev/null")
+  uri.origin(parsed)
+  |> should.equal(Error(Nil))
+}