From 0d06e096c5514e1d3032a31c6102b1984ea27df1 Mon Sep 17 00:00:00 2001
From: Filip Tibell <filip.tibell@gmail.com>
Date: Thu, 20 Apr 2023 08:52:54 +0200
Subject: [PATCH] Make _VERSION global consistently formatted and add runtime
 version to it

---
 CHANGELOG.md                   | 10 +++++++
 packages/lib/src/lua/create.rs | 20 ++++++++++++++
 packages/lib/src/tests.rs      |  1 +
 tests/globals/version.luau     | 50 ++++++++++++++++++++++++++++++++++
 4 files changed, 81 insertions(+)
 create mode 100644 tests/globals/version.luau

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f404bf2..c3dd5f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Changed
+
+-   The `_VERSION` global now follows a consistent format `Lune x.y.z+luau` to allow libraries to check against it for version requirements.
+
+    Examples:
+
+    -   `Lune 0.0.0+0`
+    -   `Lune 1.0.0+500`
+    -   `Lune 0.11.22+9999`
+
 ### Fixed
 
 -   Fixed using instances as keys in tables
diff --git a/packages/lib/src/lua/create.rs b/packages/lib/src/lua/create.rs
index 5c97488..c618adc 100644
--- a/packages/lib/src/lua/create.rs
+++ b/packages/lib/src/lua/create.rs
@@ -119,6 +119,26 @@ pub fn create() -> LuaResult<&'static Lua> {
         .set_environment(dbg_trace_env)?
         .into_function()?;
     lua.set_named_registry_value("dbg.trace", dbg_trace_fn)?;
+    // Modify the _VERSION global to also contain the current version of Lune
+    let luau_version_full = globals
+        .get::<_, LuaString>("_VERSION")
+        .expect("Missing _VERSION global");
+    let luau_version = luau_version_full
+        .to_str()?
+        .strip_prefix("Luau 0.")
+        .expect("_VERSION global is formatted incorrectly")
+        .trim();
+    if luau_version.is_empty() {
+        panic!("_VERSION global is missing version number")
+    }
+    globals.set(
+        "_VERSION",
+        lua.create_string(&format!(
+            "Lune {lune}+{luau}",
+            lune = env!("CARGO_PKG_VERSION"),
+            luau = luau_version,
+        ))?,
+    )?;
     // All done
     Ok(lua)
 }
diff --git a/packages/lib/src/tests.rs b/packages/lib/src/tests.rs
index 3a24bc3..846b88c 100644
--- a/packages/lib/src/tests.rs
+++ b/packages/lib/src/tests.rs
@@ -75,6 +75,7 @@ create_tests! {
     global_pcall: "globals/pcall",
     global_type: "globals/type",
     global_typeof: "globals/typeof",
+    global_version: "globals/version",
     serde_json_decode: "serde/json/decode",
     serde_json_encode: "serde/json/encode",
     serde_toml_decode: "serde/toml/decode",
diff --git a/tests/globals/version.luau b/tests/globals/version.luau
new file mode 100644
index 0000000..4641f4e
--- /dev/null
+++ b/tests/globals/version.luau
@@ -0,0 +1,50 @@
+-- _VERSION global should follow the following format:
+--[[
+	_VERSION global must have the following format:
+
+	Lune LUNE_MAJOR.LUNE_MINOR.LUNE_PATCH+LUAU_VERSION
+
+	Examples:
+
+	Lune 0.0.0+0
+	Lune 1.0.0+500
+	Lune 0.11.22+9999
+]]
+
+assert(_VERSION ~= nil, "_VERSION global is missing")
+assert(type(_VERSION) == "string", "_VERSION global must be a string")
+
+assert(string.sub(_VERSION, 1, 5) == "Lune ", "_VERSION global must start with 'Lune '")
+
+local withoutPrefix = string.sub(_VERSION, 6)
+local versions = string.split(withoutPrefix, "+")
+assert(versions[1] ~= nil, "_VERSION global does not contain lune version")
+assert(versions[2] ~= nil, "_VERSION global does not contain luau version")
+
+local luneVersion = string.split(versions[1], ".")
+assert(luneVersion[1] ~= nil, "_VERSION global is missing lune major version")
+assert(luneVersion[2] ~= nil, "_VERSION global is missing lune minor version")
+assert(luneVersion[3] ~= nil, "_VERSION global is missing lune patch version")
+
+assert(
+	string.find(versions[2], ".", 1, true) == nil,
+	"_VERSION global contains more than one semver partial for luau version"
+)
+
+assert(tonumber(luneVersion[1]) ~= nil, "_VERSION global lune major version is not a number")
+assert(tonumber(luneVersion[2]) ~= nil, "_VERSION global lune minor version is not a number")
+assert(tonumber(luneVersion[3]) ~= nil, "_VERSION global lune patch version is not a number")
+assert(tonumber(versions[2]) ~= nil, "_VERSION global luau version is not a number")
+
+local rebuilt = string.format(
+	"Lune %d.%d.%d+%d",
+	tonumber(luneVersion[1]) :: number,
+	tonumber(luneVersion[2]) :: number,
+	tonumber(luneVersion[3]) :: number,
+	tonumber(versions[2]) :: number
+)
+
+print("_VERSION:", _VERSION)
+print("Rebuilt:", rebuilt)
+
+assert(rebuilt == _VERSION)