From 8802abde195863def869c3608b92da9e3497b10b Mon Sep 17 00:00:00 2001
From: Lexus Drumgold <unicornware@flexdevelopment.llc>
Date: Sun, 4 Sep 2022 17:36:31 -0400
Subject: [PATCH] feat(utils): `resolveAliases`

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>
---
 .../resolve-aliases.functional.spec.ts        | 80 +++++++++++++++++++
 src/utils/resolve-aliases.ts                  | 73 +++++++++++++++++
 2 files changed, 153 insertions(+)
 create mode 100644 src/utils/__tests__/resolve-aliases.functional.spec.ts
 create mode 100644 src/utils/resolve-aliases.ts

diff --git a/src/utils/__tests__/resolve-aliases.functional.spec.ts b/src/utils/__tests__/resolve-aliases.functional.spec.ts
new file mode 100644
index 00000000..a3283062
--- /dev/null
+++ b/src/utils/__tests__/resolve-aliases.functional.spec.ts
@@ -0,0 +1,80 @@
+/**
+ * @file Functional Tests - resolveAliases
+ * @module mkbuild/utils/tests/functional/resolveAliases
+ */
+
+import path from 'node:path'
+import type { OutputFile, Statement } from 'src/interfaces'
+import { createMatchPath, loadConfig } from 'tsconfig-paths'
+import resolveAlias from '../resolve-alias'
+import testSubject from '../resolve-aliases'
+
+vi.mock('pathe')
+
+vi.mock('tsconfig-paths', async () => {
+  type Actual = typeof import('tsconfig-paths')
+  const path: string = 'tsconfig-paths'
+
+  const { createMatchPath, loadConfig } = await vi.importActual<Actual>(path)
+
+  return {
+    createMatchPath: vi.fn(createMatchPath),
+    loadConfig: vi.fn(loadConfig)
+  }
+})
+
+vi.mock('../resolve-alias', async () => {
+  type Actual = typeof import('../resolve-alias')
+  const path: string = '../resolve-alias'
+
+  const { default: resolveAlias } = await vi.importActual<Actual>(path)
+
+  return { default: vi.fn(resolveAlias) }
+})
+
+describe('functional:utils/resolveAliases', () => {
+  describe('noop', () => {
+    it('should do nothing if output content is undefined', async () => {
+      // Act
+      await testSubject({} as OutputFile)
+
+      // Expect
+      expect(loadConfig).toHaveBeenCalledTimes(0)
+      expect(createMatchPath).toHaveBeenCalledTimes(0)
+      expect(resolveAlias).toHaveBeenCalledTimes(0)
+    })
+
+    it('should do nothing if statements is empty array', async () => {
+      // Act
+      await testSubject({ contents: 'contents' } as OutputFile)
+
+      // Expect
+      expect(loadConfig).toHaveBeenCalledTimes(0)
+      expect(createMatchPath).toHaveBeenCalledTimes(0)
+      expect(resolveAlias).toHaveBeenCalledTimes(0)
+    })
+  })
+
+  describe('resolve', () => {
+    it('should resolve path aliases in output content', async () => {
+      const statements: Pick<Statement, 'code' | 'specifier'>[] = [
+        {
+          code: "import { MODULE_EXTENSIONS } from 'src/config/constants'",
+          specifier: 'src/config/constants'
+        }
+      ]
+      const output: Pick<OutputFile, 'contents' | 'src'> = {
+        contents: statements[0]!.code,
+        src: path.resolve('utils/resolve-alias.ts')
+      }
+
+      // Act
+      await testSubject(output, statements)
+
+      // Expect
+      expect(loadConfig).toHaveBeenCalledTimes(1)
+      expect(createMatchPath).toHaveBeenCalledTimes(1)
+      expect(resolveAlias).toHaveBeenCalledTimes(statements.length)
+    })
+  })
+})
diff --git a/src/utils/resolve-aliases.ts b/src/utils/resolve-aliases.ts
new file mode 100644
index 00000000..8c36d062
--- /dev/null
+++ b/src/utils/resolve-aliases.ts
@@ -0,0 +1,73 @@
+/**
+ * @file Utilities - resolveAliases
+ * @module mkbuild/utils/resolveAliases
+ */
+
+import type { BuildOptions, OutputFile, Statement } from 'src/interfaces'
+import type { ConfigLoaderResult, MatchPath } from 'tsconfig-paths'
+import resolveAlias from './resolve-alias'
+
+/**
+ * Resolves path aliases in `output.contents`.
+ *
+ * @see https://github.com/dividab/tsconfig-paths
+ *
+ * @async
+ *
+ * @param {Pick<OutputFile, 'contents' | 'src'>} output - Output file object
+ * @param {string | undefined} [output.contents] - Output file content
+ * @param {string} output.src - Full path to source file
+ * @param {Pick<Statement, 'code' | 'specifier'>[]} [statements=[]] - `import`,
+ * `require`, and `export` statements in `output.contents`
+ * @param {BuildOptions['cwd']} [cwd=process.cwd()] - Root project directory
+ * @return {Promise<void>} Nothing when complete
+ */
+const resolveAliases = async (
+  output: Pick<OutputFile, 'contents' | 'src'>,
+  statements: Pick<Statement, 'code' | 'specifier'>[] = [],
+  cwd: BuildOptions['cwd'] = process.cwd()
+): Promise<string | undefined> => {
+  if (!output.contents || statements.length === 0) return output.contents
+
+  const { createMatchPath, loadConfig } = await import('tsconfig-paths')
+
+  /**
+   * `tsconfig-paths` config loader result.
+   *
+   * @const {ConfigLoaderResult} tsconfig
+   */
+  const tsconfig: ConfigLoaderResult = loadConfig(cwd)
+
+  if (tsconfig.resultType === 'success') {
+    /**
+     * Matches a path alias.
+     *
+     * @const {MatchPath} matcher
+     */
+    const matcher: MatchPath = createMatchPath(
+      tsconfig.absoluteBaseUrl,
+      tsconfig.paths,
+      tsconfig.mainFields,
+      tsconfig.addMatchAll
+    )
+
+    for (const statement of statements) {
+      /**
+       * {@link statement.code} before path alias replacement.
+       *
+       * @const {string} code
+       */
+      const code: string = statement.code
+
+      // resolve path alias
+      resolveAlias(statement, output.src, matcher)
+
+      // replace code in output content
+      output.contents = output.contents.replace(code, statement.code)
+    }
+  }
+
+  return output.contents
+}
+
+export default resolveAliases