Prepare home-grown persistent metadata for merge with RA one

Author: Xanewok

src/rust-analyzer/persistent_state.ts

@@ -0,0 +1,69 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { promisify } from 'util';
+
+const stat = promisify(fs.stat);
+const mkdir = promisify(fs.mkdir);
+const readFile = promisify(fs.readFile);
+const writeFile = promisify(fs.writeFile);
+
+/** Returns a path where persistent data for rust-analyzer should be installed. */
+function metadataDir(): string | undefined {
+  if (process.platform === 'linux' || process.platform === 'darwin') {
+    // Prefer, in this order:
+    // 1. $XDG_CONFIG_HOME/rust-analyzer
+    // 2. $HOME/.config/rust-analyzer
+    const { HOME, XDG_CONFIG_HOME } = process.env;
+    const baseDir = XDG_CONFIG_HOME || (HOME && path.join(HOME, '.config'));
+
+    return baseDir && path.resolve(path.join(baseDir, 'rust-analyzer'));
+  } else if (process.platform === 'win32') {
+    // %LocalAppData%\rust-analyzer\
+    const { LocalAppData } = process.env;
+    return (
+      LocalAppData && path.resolve(path.join(LocalAppData, 'rust-analyzer'))
+    );
+  }
+
+  return undefined;
+}
+
+export interface Metadata {
+  releaseTag: string;
+}
+
+export async function readMetadata(): Promise<
+  Metadata | Record<string, unknown>
+> {
+  const stateDir = metadataDir();
+  if (!stateDir) {
+    return { kind: 'error', code: 'NotSupported' };
+  }
+
+  const filePath = path.join(stateDir, 'metadata.json');
+  if (!(await stat(filePath).catch(() => false))) {
+    return { kind: 'error', code: 'FileMissing' };
+  }
+
+  const contents = await readFile(filePath, 'utf8');
+  const obj = JSON.parse(contents) as unknown;
+  return typeof obj === 'object' ? (obj as Record<string, unknown>) : {};
+}
+
+export async function writeMetadata(config: Metadata) {
+  const stateDir = metadataDir();
+  if (!stateDir) {
+    return false;
+  }
+
+  if (!(await ensureDir(stateDir))) {
+    return false;
+  }
+
+  const filePath = path.join(stateDir, 'metadata.json');
+  return writeFile(filePath, JSON.stringify(config)).then(() => true);
+}
+
+function ensureDir(path: string) {
+  return !!path && stat(path).catch(() => mkdir(path, { recursive: true }));
+}

src/rust-analyzer/rustAnalyzer.ts

@@ -10,11 +10,10 @@ import { WorkspaceProgress } from '../extension';
 import { download, fetchRelease } from '../net';
 import * as rustup from '../rustup';
 import { Observable } from '../utils/observable';
+import { Metadata, readMetadata, writeMetadata } from './persistent_state';
 
 const stat = promisify(fs.stat);
 const mkdir = promisify(fs.mkdir);
-const readFile = promisify(fs.readFile);
-const writeFile = promisify(fs.writeFile);
 
 const REQUIRED_COMPONENTS = ['rust-src'];
 
@@ -45,27 +44,6 @@ function installDir(): string | undefined {
   return undefined;
 }
 
-/** Returns a path where persistent data for rust-analyzer should be installed. */
-function metadataDir(): string | undefined {
-  if (process.platform === 'linux' || process.platform === 'darwin') {
-    // Prefer, in this order:
-    // 1. $XDG_CONFIG_HOME/rust-analyzer
-    // 2. $HOME/.config/rust-analyzer
-    const { HOME, XDG_CONFIG_HOME } = process.env;
-    const baseDir = XDG_CONFIG_HOME || (HOME && path.join(HOME, '.config'));
-
-    return baseDir && path.resolve(path.join(baseDir, 'rust-analyzer'));
-  } else if (process.platform === 'win32') {
-    // %LocalAppData%\rust-analyzer\
-    const { LocalAppData } = process.env;
-    return (
-      LocalAppData && path.resolve(path.join(LocalAppData, 'rust-analyzer'))
-    );
-  }
-
-  return undefined;
-}
-
 function ensureDir(path: string) {
   return !!path && stat(path).catch(() => mkdir(path, { recursive: true }));
 }
@@ -77,40 +55,6 @@ interface RustAnalyzerConfig {
   };
 }
 
-interface Metadata {
-  releaseTag: string;
-}
-
-async function readMetadata(): Promise<Metadata | Record<string, unknown>> {
-  const stateDir = metadataDir();
-  if (!stateDir) {
-    return { kind: 'error', code: 'NotSupported' };
-  }
-
-  const filePath = path.join(stateDir, 'metadata.json');
-  if (!(await stat(filePath).catch(() => false))) {
-    return { kind: 'error', code: 'FileMissing' };
-  }
-
-  const contents = await readFile(filePath, 'utf8');
-  const obj = JSON.parse(contents) as unknown;
-  return typeof obj === 'object' ? (obj as Record<string, unknown>) : {};
-}
-
-async function writeMetadata(config: Metadata) {
-  const stateDir = metadataDir();
-  if (!stateDir) {
-    return false;
-  }
-
-  if (!(await ensureDir(stateDir))) {
-    return false;
-  }
-
-  const filePath = path.join(stateDir, 'metadata.json');
-  return writeFile(filePath, JSON.stringify(config)).then(() => true);
-}
-
 export async function getServer({
   askBeforeDownload,
   package: pkg,