From 8ec36f1e2bdea337236048170a356ec034eaa046 Mon Sep 17 00:00:00 2001
From: Marshall Bowers <elliott.codes@gmail.com>
Date: Tue, 27 Aug 2024 11:10:58 -0400
Subject: [PATCH] extension: Define capabilities in the extension manifest
 (#16953)

This PR adds an initial notion of extension capabilities.

Capabilities are used to express the operations an extension is capable
of doing. This will provide further insights into what an extension can
do, as well as provide the ability to grant or deny the set of
capabilities.

Capabilities are defined in the `capabilities` field in the extension
manifest. This field contains an array of capabilities.

Each capability has a `kind` to denote the known capability it
corresponds to. Individual capabilities may have additional fields,
based on the `kind`.

Here's an example of some capabilities:

```toml
capabilities = [
    { kind = "download-file", host = "github.com", path_prefix = "owner/repo" },
    { kind = "npm:install", package = "@vue/language-server" },
]
```

In order to avoid a breaking change, the `capabilities` field is
currently optional and defaults to an empty array. This will allow us to
add support for extensions to define capabilities before we start
enforcing them.

Release Notes:

- N/A
---
 crates/extension/src/extension_manifest.rs   | 25 ++++++++++++++++++++
 crates/extension/src/extension_store_test.rs |  3 +++
 extensions/gleam/extension.toml              |  4 ++++
 3 files changed, 32 insertions(+)

diff --git a/crates/extension/src/extension_manifest.rs b/crates/extension/src/extension_manifest.rs
index 9d8a841686..b4416db574 100644
--- a/crates/extension/src/extension_manifest.rs
+++ b/crates/extension/src/extension_manifest.rs
@@ -64,6 +64,8 @@ pub struct ExtensionManifest {
     #[serde(default)]
     pub authors: Vec<String>,
     #[serde(default)]
+    pub capabilities: Vec<ExtensionCapability>,
+    #[serde(default)]
     pub lib: LibManifestEntry,
 
     #[serde(default)]
@@ -82,6 +84,28 @@ pub struct ExtensionManifest {
     pub snippets: Option<PathBuf>,
 }
 
+/// A capability for an extension.
+#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize)]
+#[serde(tag = "kind")]
+pub enum ExtensionCapability {
+    /// The capability to download a file from a server.
+    #[serde(rename = "download-file")]
+    DownloadFile {
+        /// The host name of the server from which the file will be downloaded (e.g., `github.com`).
+        host: String,
+        /// The path prefix to the file that will be downloaded.
+        ///
+        /// Any path that starts with this prefix will be allowed.
+        path_prefix: String,
+    },
+    /// The capability to install a package from npm.
+    #[serde(rename = "npm:install")]
+    NpmInstall {
+        /// The name of the package.
+        package: String,
+    },
+}
+
 #[derive(Clone, Default, PartialEq, Eq, Debug, Deserialize, Serialize)]
 pub struct LibManifestEntry {
     pub kind: Option<ExtensionLibraryKind>,
@@ -186,6 +210,7 @@ fn manifest_from_old_manifest(
         repository: manifest_json.repository,
         authors: manifest_json.authors,
         schema_version: SchemaVersion::ZERO,
+        capabilities: Vec::new(),
         lib: Default::default(),
         themes: {
             let mut themes = manifest_json.themes.into_values().collect::<Vec<_>>();
diff --git a/crates/extension/src/extension_store_test.rs b/crates/extension/src/extension_store_test.rs
index d4227c05f9..1a6fb253f0 100644
--- a/crates/extension/src/extension_store_test.rs
+++ b/crates/extension/src/extension_store_test.rs
@@ -150,6 +150,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                         authors: Vec::new(),
                         repository: None,
                         themes: Default::default(),
+                        capabilities: Vec::new(),
                         lib: Default::default(),
                         languages: vec!["languages/erb".into(), "languages/ruby".into()],
                         grammars: [
@@ -181,6 +182,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                             "themes/monokai-pro.json".into(),
                             "themes/monokai.json".into(),
                         ],
+                        capabilities: Vec::new(),
                         lib: Default::default(),
                         languages: Default::default(),
                         grammars: BTreeMap::default(),
@@ -344,6 +346,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                 authors: vec![],
                 repository: None,
                 themes: vec!["themes/gruvbox.json".into()],
+                capabilities: Vec::new(),
                 lib: Default::default(),
                 languages: Default::default(),
                 grammars: BTreeMap::default(),
diff --git a/extensions/gleam/extension.toml b/extensions/gleam/extension.toml
index 7cedbca5d4..6fac2ade2e 100644
--- a/extensions/gleam/extension.toml
+++ b/extensions/gleam/extension.toml
@@ -6,6 +6,10 @@ schema_version = 1
 authors = ["Marshall Bowers <elliott.codes@gmail.com>"]
 repository = "https://github.com/zed-industries/zed"
 
+capabilities = [
+    { kind = "download-file", host = "github.com", path_prefix = "gleam-lang/gleam" },
+]
+
 [language_servers.gleam]
 name = "Gleam LSP"
 language = "Gleam"