feat(shared-ini-file-loader): refactor loadSharedConfigFiles into modular components (#3285)

Author: trivikr

Diff for: packages/shared-ini-file-loader/src/getHomeDir.spec.ts

@@ -0,0 +1,62 @@
+import { homedir } from "os";
+import { sep } from "path";
+
+import { getHomeDir } from "./getHomeDir";
+
+jest.mock("os");
+
+describe(getHomeDir.name, () => {
+  const mockHOME = "mockHOME";
+  const mockUSERPROFILE = "mockUSERPROFILE";
+  const mockHOMEPATH = "mockHOMEPATH";
+  const mockHOMEDRIVE = "mockHOMEDRIVE";
+  const mockHomeDir = "mockHomeDir";
+
+  const OLD_ENV = process.env;
+
+  beforeEach(() => {
+    (homedir as jest.Mock).mockReturnValue(mockHomeDir);
+    process.env = {
+      ...OLD_ENV,
+      HOME: mockHOME,
+      USERPROFILE: mockUSERPROFILE,
+      HOMEPATH: mockHOMEPATH,
+      HOMEDRIVE: mockHOMEDRIVE,
+    };
+  });
+
+  afterEach(() => {
+    process.env = OLD_ENV;
+    jest.clearAllMocks();
+    jest.resetModules();
+  });
+
+  it("returns value in process.env.HOME first", () => {
+    expect(getHomeDir()).toEqual(mockHOME);
+  });
+
+  it("returns value in process.env.USERPROFILE second", () => {
+    process.env = { ...process.env, HOME: undefined };
+    expect(getHomeDir()).toEqual(mockUSERPROFILE);
+  });
+
+  describe("returns value in HOMEPATH third", () => {
+    beforeEach(() => {
+      process.env = { ...process.env, HOME: undefined, USERPROFILE: undefined };
+    });
+
+    it("uses value in process.env.HOMEDRIVE if it's set", () => {
+      expect(getHomeDir()).toEqual(`${mockHOMEDRIVE}${mockHOMEPATH}`);
+    });
+
+    it("uses default if process.env.HOMEDRIVE is not set", () => {
+      process.env = { ...process.env, HOMEDRIVE: undefined };
+      expect(getHomeDir()).toEqual(`C:${sep}${mockHOMEPATH}`);
+    });
+  });
+
+  it("returns value from homedir fourth", () => {
+    process.env = { ...process.env, HOME: undefined, USERPROFILE: undefined, HOMEPATH: undefined };
+    expect(getHomeDir()).toEqual(mockHomeDir);
+  });
+});

Diff for: packages/shared-ini-file-loader/src/getHomeDir.ts

@@ -0,0 +1,17 @@
+import { homedir } from "os";
+import { sep } from "path";
+
+/**
+ * Get the HOME directory for the current runtime.
+ *
+ * @internal
+ */
+export const getHomeDir = (): string => {
+  const { HOME, USERPROFILE, HOMEPATH, HOMEDRIVE = `C:${sep}` } = process.env;
+
+  if (HOME) return HOME;
+  if (USERPROFILE) return USERPROFILE;
+  if (HOMEPATH) return `${HOMEDRIVE}${HOMEPATH}`;
+
+  return homedir();
+};