feat(shell): add $PWD and $OLDPWD

.yarn/versions/b2c3eb43.yml

@@ -0,0 +1,35 @@
+releases:
+  "@yarnpkg/cli": minor
+  "@yarnpkg/core": minor
+  "@yarnpkg/shell": minor
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-exec"
+  - "@yarnpkg/plugin-file"
+  - "@yarnpkg/plugin-git"
+  - "@yarnpkg/plugin-github"
+  - "@yarnpkg/plugin-http"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-link"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/doctor"
+  - "@yarnpkg/extensions"
+  - "@yarnpkg/nm"
+  - "@yarnpkg/pnpify"
+  - "@yarnpkg/sdks"

packages/yarnpkg-shell/sources/index.ts

@@ -124,7 +124,10 @@ const BUILTINS = new Map<string, ShellBuiltin>([
     if (!stat.isDirectory())
       throw new ShellError(`cd: not a directory: ${target}`);
 
+    state.environment.PWD = npath.fromPortablePath(resolvedTarget);
+    state.environment.OLDPWD = npath.fromPortablePath(state.cwd);
     state.cwd = resolvedTarget;
+
     return 0;
   }],
 
@@ -1065,7 +1068,10 @@ export async function execute(command: string, args: Array<string> = [], {
     glob,
   }, {
     cwd,
-    environment: normalizedEnv,
+    environment: Object.assign({}, normalizedEnv, {
+      PWD: cwd,
+      OLDPWD: ``,
+    }),
     exitCode: null,
     procedures: {},
     stdin,

packages/yarnpkg-shell/tests/shell.test.ts

@@ -1,8 +1,8 @@
-import {xfs, ppath, PortablePath} from '@yarnpkg/fslib';
-import {execute, UserOptions}     from '@yarnpkg/shell';
-import {PassThrough}              from 'stream';
-import stripAnsi                  from 'strip-ansi';
-import {setTimeout}               from 'timers/promises';
+import {xfs, npath, ppath, PortablePath} from '@yarnpkg/fslib';
+import {execute, UserOptions}            from '@yarnpkg/shell';
+import {PassThrough}                     from 'stream';
+import stripAnsi                         from 'strip-ansi';
+import {setTimeout}                      from 'timers/promises';
 
 const isNotWin32 = process.platform !== `win32`;
 
@@ -576,6 +576,26 @@ describe(`Shell`, () => {
           stdout: `""\n`,
         });
       });
+
+      it(`should expose the cwd via $PWD`, async () => {
+        await xfs.mktempPromise(async tmpDir => {
+          await expectResult(bufferResult(
+            `cd ${tmpDir}; echo $PWD`,
+          ), {
+            stdout: `${npath.fromPortablePath(tmpDir)}\n`,
+          });
+        });
+      });
+
+      it(`should expose the previous cwd via $OLDPWD`, async () => {
+        await xfs.mktempPromise(async tmpDir => {
+          await expectResult(bufferResult(
+            `cd ${tmpDir}; echo $OLDPWD`,
+          ), {
+            stdout: `${process.cwd()}\n`,
+          });
+        });
+      });
     });
 
     describe(`Setting variables`, () => {