Improve package version fetching reliability (#437)

* Improve version fetching code

* fix types

* changelog

* Use pkginfo

changelog.d/437.bugfix

@@ -0,0 +1 @@
+Fix `getBridgeVersion` sometimes reporting "unknown" when the package.json is accessible.

package.json

@@ -31,10 +31,11 @@
   "homepage": "https://github.com/matrix-org/matrix-appservice-bridge#readme",
   "dependencies": {
     "@alloc/quick-lru": "^5.2.0",
-    "chalk": "^4.1.0",
+    "@types/pkginfo": "^0.4.0",
     "axios": "^0.27.2",
-    "express-rate-limit": "^6.2.0",
+    "chalk": "^4.1.0",
     "express": "^4.18.1",
+    "express-rate-limit": "^6.2.0",
     "extend": "^3.0.2",
     "ip-cidr": "^3.0.4",
     "is-my-json-valid": "^2.20.5",
@@ -44,6 +45,7 @@
     "nedb": "^1.8.0",
     "nopt": "^5.0.0",
     "p-queue": "^6.6.2",
+    "pkginfo": "^0.4.1",
     "prom-client": "^14.0.0",
     "uuid": "^8.3.2",
     "winston": "^3.3.3",

src/utils/package-info.ts

@@ -1,5 +1,12 @@
-import { join, resolve } from "path";
-let BridgeVersion: string;
+import { join, dirname } from "path";
+import { statSync } from "fs";
+import pkginfo from "pkginfo";
+import Logging from "../components/logging";
+
+const log = Logging.get("PackageInfo");
+
+// This may be defined if the script is run via NPM: https://docs.npmjs.com/cli/v8/using-npm/scripts#packagejson-vars
+let BridgeVersion: string|undefined = process.env.npm_package_version;
 
 /**
  * Forcibly set the version of the bridge, for use by other components.
@@ -11,23 +18,47 @@ export function setBridgeVersion(version: string): void {
     BridgeVersion = version;
 }
 
+/**
+ * Try to determine the path of the `package.json` file for the current
+ * running module. Iterates through parent directories of `require.main.filename`
+ * until it finds a package.json. This **may** result in false positives.
+ * @returns The path to a package.json file, or undefined if one could not be found.
+ */
+export function identifyPackageFile(): string|undefined {
+    // Find the main module path first
+    let mainModulePath = require.main?.filename;
+    if (!mainModulePath) {
+        return undefined;
+    }
+    do {
+        mainModulePath = dirname(mainModulePath);
+        try {
+            const packagePath = join(mainModulePath, 'package.json');
+            statSync(packagePath);
+            return packagePath;
+        }
+        catch (ex) {
+            continue;
+        }
+    } while (mainModulePath !== '/')
+    return undefined;
+}
+
 /**
  * Get the current version of the bridge from the package.json file.
+ * By default this uses `identifyPackageFile` to determine the file.
  * @param packageJsonPath The path to the package.json of the bridge.
  * @returns Either the version number, or unknown.
  */
-export function getBridgeVersion(packageJsonPath = "./package.json"): string {
+export function getBridgeVersion(packageJsonPath?: string): string {
     if (BridgeVersion) {
         return BridgeVersion;
     }
-    packageJsonPath = join(resolve(packageJsonPath));
-    try {
-        // eslint-disable-next-line @typescript-eslint/no-var-requires
-        const nodePackage = require(packageJsonPath);
-        BridgeVersion = nodePackage.version;
-    }
-    catch (err) {
-        BridgeVersion = "unknown";
-    }
-    return BridgeVersion;
+    BridgeVersion = require.main && pkginfo.read(
+        require.main,
+        packageJsonPath && dirname(packageJsonPath)
+    )?.package.version || "unknown";
+
+    // Need to be explicit here due to the type of the static BridgeVersion
+    return BridgeVersion as string;
 }

yarn.lock

@@ -444,6 +444,13 @@
   resolved "https://registry.yarnpkg.com/@types/nopt/-/nopt-3.0.29.tgz#f19df3db4c97ee1459a2740028320a71d70964ce"
   integrity sha512-PAO73Sc7+IiTIuPY1r/l+TgdIK4lugz5QxPaQ25EsjBBuZAw8OOtNEEGXvGciYwWa+JBE5wNQ8mR6nJE+H2csQ==
 
+"@types/pkginfo@^0.4.0":
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/@types/pkginfo/-/pkginfo-0.4.0.tgz#00143b97e98aa7c9391943266d2e4aebd8f44c35"
+  integrity sha512-4DGKkOlWkMuVDZQvytWzzWWAjyqDmlLKRYE4lzeA8t0s7fK0aF25uPbX9eBVermUjLJdeLHu9k1WmNiAssqCcg==
+  dependencies:
+    "@types/node" "*"
+
 "@types/qs@*":
   version "6.9.7"
   resolved "https://registry.yarnpkg.com/@types/qs/-/qs-6.9.7.tgz#63bb7d067db107cc1e457c303bc25d511febf6cb"
@@ -2588,6 +2595,11 @@ pkg-dir@^4.1.0:
   dependencies:
     find-up "^4.0.0"
 
+pkginfo@^0.4.1:
+  version "0.4.1"
+  resolved "https://registry.yarnpkg.com/pkginfo/-/pkginfo-0.4.1.tgz#b5418ef0439de5425fc4995042dced14fb2a84ff"
+  integrity sha512-8xCNE/aT/EXKenuMDZ+xTVwkT8gsoHN2z/Q29l80u0ppGEXVvsKRzNMbtKhg8LS8k1tJLAHHylf6p4VFmP6XUQ==
+
 postcss@^8.3.11:
   version "8.4.14"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.14.tgz#ee9274d5622b4858c1007a74d76e42e56fd21caf"