refactor(data_dir): simplify logic and make code robust and testable

spec-es6/data_dir.spec.ts

@@ -0,0 +1,138 @@
+import { describe, it, execute, expect } from "./mini_test.ts";
+
+import { getPlatformAppDataDir, getDataDirs} from "../src/services/data_dir.ts"
+
+
+
+describe("data_dir.ts unit tests", () => {
+
+  describe("#getPlatformAppDataDir()", () => {
+
+    type TestCaseGetPlatformAppDataDir = [
+      description: string,
+      fnValue: Parameters<typeof getPlatformAppDataDir>, 
+      expectedValueFn: (val: ReturnType<typeof getPlatformAppDataDir>) => boolean
+    ]
+    const testCases: TestCaseGetPlatformAppDataDir[] = [
+
+      [
+        "w/ unsupported OS it should return 'null'",
+        ["aix", undefined], 
+        (val) => val === null 
+      ],
+
+      [
+        "w/ win32 and no APPDATA set it should return 'null'",
+        ["win32", undefined],
+        (val) => val === null
+      ],
+
+      [
+        "w/ win32 and set APPDATA it should return set 'APPDATA'",
+        ["win32", "AppData"],
+        (val) => val === "AppData"
+      ],
+
+      [
+        "w/ linux it should return '/.local/share'",
+        ["linux", undefined],
+        (val) => val !== null && val.endsWith("/.local/share")
+      ],
+
+      [
+        "w/ linux and wrongly set APPDATA it should ignore APPDATA and return /.local/share",
+        ["linux", "FakeAppData"],
+        (val) => val !== null && val.endsWith("/.local/share")
+      ],
+
+      [
+        "w/ darwin it should return /Library/Application Support",
+        ["darwin", undefined],
+        (val) => val !== null && val.endsWith("/Library/Application Support")
+      ],
+    ];
+
+      testCases.forEach(testCase => {
+        const [testDescription, value, isExpected] = testCase;
+        return it(testDescription, () => {
+          const actual = getPlatformAppDataDir(...value);
+          const result = isExpected(actual);
+          expect(result).toBeTruthy()
+
+        })
+      })
+
+
+  })
+
+  describe("#getTriliumDataDir", () => {
+    // TODO
+  })
+
+  describe("#getDataDirs()", () => {
+
+    const envKeys: Omit<keyof ReturnType<typeof getDataDirs>, "TRILIUM_DATA_DIR">[] = [
+      "DOCUMENT_PATH",
+      "BACKUP_DIR",
+      "LOG_DIR",
+      "ANONYMIZED_DB_DIR",
+      "CONFIG_INI_PATH",
+    ];
+
+    const setMockedEnv = (prefix: string | null) => {
+      envKeys.forEach(key => {
+        if (prefix) {
+          process.env[`TRILIUM_${key}`] = `${prefix}_${key}`
+        } else {
+          delete process.env[`TRILIUM_${key}`]
+        }
+      })
+    };
+
+    it("w/ process.env values present, it should return an object using values from process.env", () => {
+
+      // set mocked values
+      const mockValuePrefix = "MOCK";
+      setMockedEnv(mockValuePrefix);
+
+      // get result
+      const result = getDataDirs(`${mockValuePrefix}_TRILIUM_DATA_DIR`);
+
+      for (const key in result) {
+        expect(result[key]).toEqual(`${mockValuePrefix}_${key}`)
+      }
+    })
+
+    it("w/ NO process.env values present, it should return an object using supplied TRILIUM_DATA_DIR as base", () => {
+
+      // make sure values are undefined
+      setMockedEnv(null);
+
+      const mockDataDir = "/home/test/MOCK_TRILIUM_DATA_DIR"
+      const result = getDataDirs(mockDataDir);
+
+      for (const key in result) {
+        expect(result[key].startsWith(mockDataDir)).toBeTruthy()
+      }
+    })
+
+    it("should ignore attempts to change a property on the returned object", () => {
+
+      // make sure values are undefined
+      setMockedEnv(null);
+
+      const mockDataDir = "/home/test/MOCK_TRILIUM_DATA_DIR"
+      const result = getDataDirs(mockDataDir);
+
+      //@ts-expect-error - attempt to change value of readonly property
+      result.BACKUP_DIR = "attempt to change";
+
+      for (const key in result) {
+        expect(result[key].startsWith(mockDataDir)).toBeTruthy()
+      }
+    })
+  })
+
+});
+
+execute()

src/services/data_dir.ts

@@ -2,75 +2,83 @@
 
 /*
  * This file resolves trilium data path in this order of priority:
- * - if TRILIUM_DATA_DIR environment variable exists, then its value is used as the path
- * - if "trilium-data" dir exists directly in the home dir, then it is used
- * - based on OS convention, if the "app data directory" exists, we'll use or create "trilium-data" directory there
- * - as a fallback if the previous step fails, we'll use home dir
+ * - case A) if TRILIUM_DATA_DIR environment variable exists, then its value is used as the path
+ * - case B) if "trilium-data" dir exists directly in the home dir, then it is used
+ * - case C) based on OS convention, if the "app data directory" exists, we'll use or create "trilium-data" directory there
+ * - case D) as a fallback if the previous step fails, we'll use home dir
  */
 
 import os from "os";
 import fs from "fs";
-import path from "path";
+import { join as pathJoin } from "path";
 
-function getAppDataDir() {
-    let appDataDir = os.homedir(); // fallback if OS is not recognized
+const DIR_NAME = "trilium-data";
+const FOLDER_PERMISSIONS = 0o700;
 
-    if (os.platform() === "win32" && process.env.APPDATA) {
-        appDataDir = process.env.APPDATA;
-    } else if (os.platform() === "linux") {
-        appDataDir = `${os.homedir()}/.local/share`;
-    } else if (os.platform() === "darwin") {
-        appDataDir = `${os.homedir()}/Library/Application Support`;
+export function getTriliumDataDir(dataDirName: string) {
+    // case A
+    if (process.env.TRILIUM_DATA_DIR) {
+        createDirIfNotExisting(process.env.TRILIUM_DATA_DIR);
+        return process.env.TRILIUM_DATA_DIR;
     }
 
-    if (!fs.existsSync(appDataDir)) {
-        // expected app data path doesn't exist, let's use fallback
-        appDataDir = os.homedir();
+    // case B
+    const homePath = pathJoin(os.homedir(), dataDirName);
+    if (fs.existsSync(homePath)) {
+        return homePath;
     }
 
-    return appDataDir;
+    // case C
+    const platformAppDataDir = getPlatformAppDataDir(os.platform(), process.env.APPDATA);
+    if (platformAppDataDir && fs.existsSync(platformAppDataDir)) {
+        const appDataDirPath = pathJoin(platformAppDataDir, dataDirName);
+        createDirIfNotExisting(appDataDirPath);
+        return appDataDirPath;
+    }
+
+    // case D
+    createDirIfNotExisting(homePath);
+    return homePath;
 }
 
-const DIR_NAME = "trilium-data";
+export function getDataDirs(TRILIUM_DATA_DIR: string) {
+    const dataDirs = {
+        TRILIUM_DATA_DIR: TRILIUM_DATA_DIR,
+        DOCUMENT_PATH: process.env.TRILIUM_DOCUMENT_PATH || pathJoin(TRILIUM_DATA_DIR, "document.db"),
+        BACKUP_DIR: process.env.TRILIUM_BACKUP_DIR || pathJoin(TRILIUM_DATA_DIR, "backup"),
+        LOG_DIR: process.env.TRILIUM_LOG_DIR || pathJoin(TRILIUM_DATA_DIR, "log"),
+        ANONYMIZED_DB_DIR: process.env.TRILIUM_ANONYMIZED_DB_DIR || pathJoin(TRILIUM_DATA_DIR, "anonymized-db"),
+        CONFIG_INI_PATH: process.env.TRILIUM_CONFIG_INI_PATH || pathJoin(TRILIUM_DATA_DIR, "config.ini")
+    } as const;
+
+    Object.freeze(dataDirs);
+    return dataDirs;
+}
 
-function getTriliumDataDir() {
-    if (process.env.TRILIUM_DATA_DIR) {
-        if (!fs.existsSync(process.env.TRILIUM_DATA_DIR)) {
-            fs.mkdirSync(process.env.TRILIUM_DATA_DIR, 0o700);
-        }
+export function getPlatformAppDataDir(platform: ReturnType<typeof os.platform>, ENV_APPDATA_DIR: string | undefined = process.env.APPDATA) {
+    switch (true) {
+        case platform === "win32" && !!ENV_APPDATA_DIR:
+            return ENV_APPDATA_DIR;
 
-        return process.env.TRILIUM_DATA_DIR;
-    }
+        case platform === "linux":
+            return `${os.homedir()}/.local/share`;
 
-    const homePath = os.homedir() + path.sep + DIR_NAME;
+        case platform === "darwin":
+            return `${os.homedir()}/Library/Application Support`;
 
-    if (fs.existsSync(homePath)) {
-        return homePath;
+        default:
+            // if OS is not recognized
+            return null;
     }
+}
 
-    const appDataPath = getAppDataDir() + path.sep + DIR_NAME;
-
-    if (!fs.existsSync(appDataPath)) {
-        fs.mkdirSync(appDataPath, 0o700);
+function createDirIfNotExisting(path: fs.PathLike, permissionMode: fs.Mode = FOLDER_PERMISSIONS) {
+    if (!fs.existsSync(path)) {
+        fs.mkdirSync(path, permissionMode);
     }
-
-    return appDataPath;
 }
 
-const TRILIUM_DATA_DIR = getTriliumDataDir();
-const DIR_SEP = TRILIUM_DATA_DIR + path.sep;
-
-const DOCUMENT_PATH = process.env.TRILIUM_DOCUMENT_PATH || `${DIR_SEP}document.db`;
-const BACKUP_DIR = process.env.TRILIUM_BACKUP_DIR || `${DIR_SEP}backup`;
-const LOG_DIR = process.env.TRILIUM_LOG_DIR || `${DIR_SEP}log`;
-const ANONYMIZED_DB_DIR = process.env.TRILIUM_ANONYMIZED_DB_DIR || `${DIR_SEP}anonymized-db`;
-const CONFIG_INI_PATH = process.env.TRILIUM_CONFIG_INI_PATH || `${DIR_SEP}config.ini`;
-
-export default {
-    TRILIUM_DATA_DIR,
-    DOCUMENT_PATH,
-    BACKUP_DIR,
-    LOG_DIR,
-    ANONYMIZED_DB_DIR,
-    CONFIG_INI_PATH
-};
+const TRILIUM_DATA_DIR = getTriliumDataDir(DIR_NAME);
+const dataDirs = getDataDirs(TRILIUM_DATA_DIR);
+
+export default dataDirs;