Add ts-plugin (#114)

grats-ts-plugin/README.md

@@ -0,0 +1,3 @@
+# grats-ts-plugin
+
+Experimental TypeScript plugin for Grats. This plugin is not ready for production use.

grats-ts-plugin/index.js

@@ -0,0 +1,11 @@
+"use strict";
+
+// TypeScript is vary particular about how plugins are structured. They must be
+// CommonJS and they must have a single value for `module.exports`. Additionally,
+// the plugin must be a plain module name (no `/` characters allowed).
+//
+// However, the logic for the plugin is tightly coupled with Grats itself and
+// should really live (and ship) alongside each version of Grats. While
+// I continue to struggle with figuring out how to let Grats operate as its own
+// TypeScript plugin, this package is just a shim.
+module.exports = require("grats").initTsPlugin;

grats-ts-plugin/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "grats-ts-plugin",
+  "version": "0.0.2",
+  "license": "MIT",
+  "main": "./",
+  "module": "./index.js",
+  "peerDependencies": {
+    "grats": ">=0.0.19"
+  },
+  "prettier": {}
+}

pnpm-workspace.yaml

@@ -1,3 +1,4 @@
 packages:
   - 'website'
-  - 'examples/*'
+  - 'examples/*'
+  - 'grats-ts-plugin'

src/lib.ts

@@ -31,6 +31,7 @@ import { applyDefaultNullability } from "./transforms/applyDefaultNullability";
 import { mergeExtensions } from "./transforms/mergeExtensions";
 import { sortSchemaAst } from "./transforms/sortSchemaAst";
 import { validateSemanticNullability } from "./validations/validateSemanticNullability";
+export { initTsPlugin } from "./tsPlugin/initTsPlugin";
 
 export type SchemaAndDoc = {
   schema: GraphQLSchema;

src/tsPlugin/initTsPlugin.ts

@@ -0,0 +1,43 @@
+import type * as TS from "typescript/lib/tsserverlibrary";
+import { extract } from "../Extractor";
+
+// An experimental plugin for TypeScript that adds a new language service
+// which reports diagnostics for the current file. Currently it only reports
+// syntax errors because semantic errors are too expensive to compute on each
+// keystroke.
+export function initTsPlugin(modules: { typescript: typeof TS }) {
+  const ts = modules.typescript;
+
+  function create(info: TS.server.PluginCreateInfo): TS.LanguageService {
+    const projectRoot = info.project.getCurrentDirectory();
+    info.project.projectService.logger.info(
+      `Grats: Initializing Plugin with project root: ${projectRoot} and TypeScript version: ${ts.version}`,
+    );
+
+    // Set up decorator object
+    const proxy: TS.LanguageService = Object.create(null);
+    for (const k of Object.keys(info.languageService) as Array<
+      keyof TS.LanguageService
+    >) {
+      const x = info.languageService[k];
+      // @ts-expect-error
+      proxy[k] = (...args: Array<any>) => x.apply(info.languageService, args);
+    }
+
+    proxy.getSyntacticDiagnostics = (filename): TS.DiagnosticWithLocation[] => {
+      const prior = info.languageService.getSyntacticDiagnostics(filename);
+      const doc = info.languageService.getProgram()?.getSourceFile(filename);
+
+      if (doc == null) return prior;
+      const result = extract(doc);
+
+      if (result.kind === "OK") return prior;
+
+      return [...prior, ...result.err];
+    };
+
+    return proxy;
+  }
+
+  return { create };
+}

tsconfig.json

@@ -31,6 +31,7 @@
     "src/tests/fixtures",
     "docs",
     "examples",
-    "website"
+    "website",
+    "grats-ts-plugin"
   ]
 }