feat: github plugin specifier

Author: bcheidemann

README.md

@@ -349,6 +349,21 @@ entype \
   fixtures/datapack/blockstates/*.json
 ```
 
+Alternatively, the `github:` qualifier can be used:
+
+```sh
+entype \
+  --allow-unstable \
+  --lang rust \
+  --plugin "github:bcheidemann/entype/lib/plugins/derive-debug.ts" \
+  fixtures/datapack/blockstates/*.json
+```
+
+The format is `github:<branch>@<owner>/<repo>/<path>`, where `branch` defaults
+to `main` and `path` defaults to `mod.ts`. The plugin speicifier
+`github:bcheidemann/entype-plugin-example` would be resolved to
+`https://raw.githubusercontent.com/bcheidemann/entype-plugin-example/main/mod.ts`.
+
 ## How it works
 
 Entype tries to generate the simplest possible type that accurately describes

lib/plugins/mod.ts

@@ -1,12 +1,42 @@
 import { Plugin, PluginName } from "./types.ts";
 
+export const GITHUB_PLUGIN_PREFIX = "github:";
+
 export async function loadPlugin(pluginName: PluginName): Promise<Plugin> {
   switch (pluginName) {
     case "derive-debug":
       return (await import("./derive-debug.ts")).plugin;
     case "serde-derive":
       return (await import("./serde-derive.ts")).plugin;
     default:
-      return (await import(pluginName)).plugin;
+      return await loadThirdPartyPlugin(pluginName);
   }
 }
+
+export async function loadThirdPartyPlugin(
+  pluginName: string,
+): Promise<Plugin> {
+  if (pluginName.startsWith(GITHUB_PLUGIN_PREFIX)) {
+    return await loadGithubPlugin(pluginName);
+  }
+
+  return (await import(pluginName)).plugin;
+}
+
+export async function loadGithubPlugin(
+  pluginName: string,
+): Promise<Plugin> {
+  const moduleSpecifier = pluginName.slice(GITHUB_PLUGIN_PREFIX.length);
+  const [branch, rest] = moduleSpecifier.includes("@")
+    ? moduleSpecifier.split("@")
+    : [null, moduleSpecifier];
+  const [owner, repo, ...path] = rest.split("/");
+
+  const { plugin } = await import(
+    `https://raw.githubusercontent.com/${owner}/${repo}/${branch || "main"}/${
+      path ? path.join("/") : "mod.ts"
+    }`
+  );
+
+  return plugin;
+}

main.ts

@@ -27,7 +27,7 @@ async function main(args: string[]): Promise<0 | 1> {
   }
 
   if ("version" in config) {
-    console.log("1.1.0");
+    console.log("1.2.0");
     return 0;
   }