Differentially test linear-time regexp support for migrated shells

.github/workflows/checks.yml

@@ -299,42 +299,6 @@ jobs:
         run: npm clean-install
       - name: Run integration tests
         run: npm run coverage:integration
-  test-mutation-unit:
-    name: Mutation (Unit)
-    runs-on: ubuntu-24.04
-    needs:
-      - test-unit
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
-        with:
-          persist-credentials: false
-      - name: Verify action checksums
-        uses: ./.github/actions/ghasum
-      - name: Install Node.js
-        uses: actions/setup-node@v6.3.0
-        with:
-          cache: npm
-          node-version-file: .nvmrc
-      - name: Cache Stryker incremental report
-        uses: actions/cache@v5.0.3
-        with:
-          path: .cache/stryker-incremental-unit.json
-          key: mutation-unit-${{ github.run_number }}
-          restore-keys: |
-            mutation-unit-
-      - name: Install dependencies
-        run: npm clean-install
-      - name: Run mutation tests
-        run: npm run mutation:unit
-      - name: Upload mutation report
-        uses: actions/upload-artifact@v7.0.0
-        if: ${{ failure() || success() }}
-        with:
-          name: mutation-unit-report
-          path: |
-            _reports/mutation/unit.html
-            .cache/stryker-incremental-unit.json
   test-mutation-integration:
     name: Mutation (integration)
     runs-on: ubuntu-24.04
@@ -392,6 +356,15 @@ jobs:
           node-version-file: .nvmrc
       - name: Install dependencies
         run: npm clean-install
+      - name: Run unit tests
+        run: |
+          cd node_modules/shescape-previous
+          git init .
+          git add .
+          git config --global user.name "John Doe"
+          git config --global user.email johndoe@example.com
+          git commit -m 'n/a'
+          git apply ../../2410.patch
       - name: Run unit tests
         run: npm run coverage:unit
   transpile:

2410.patch

@@ -0,0 +1,26 @@
+diff --git a/src/internal/unix/bash.js b/src/internal/unix/bash.js
+index 19fba6d..c1c57ce 100644
+--- a/src/internal/unix/bash.js
++++ b/src/internal/unix/bash.js
+@@ -15,7 +15,7 @@ function escapeArg(arg) {
+     .replace(/\n/gu, " ")
+     .replace(/\\/gu, "\\\\")
+     .replace(/(?<=^|\s)([#~])/gu, "\\$1")
+-    .replace(/(["$&'()*;<>?`{|])/gu, "\\$1")
++    .replace(/(["$&'()*;<>?`{|[\]])/gu, "\\$1")
+     .replace(/(?<=[:=])(~)(?=[\s+\-/0:=]|$)/gu, "\\$1")
+     .replace(/([\t ])/gu, "\\$1");
+ }
+diff --git a/src/internal/unix/busybox.js b/src/internal/unix/busybox.js
+index e61262f..0c91dc4 100644
+--- a/src/internal/unix/busybox.js
++++ b/src/internal/unix/busybox.js
+@@ -15,7 +15,7 @@ function escapeArg(arg) {
+     .replace(/\n/gu, " ")
+     .replace(/\\/gu, "\\\\")
+     .replace(/(?<=^|\s)([#~])/gu, "\\$1")
+-    .replace(/(["$&'()*;<>?`|])/gu, "\\$1")
++    .replace(/(["$&'()*;<>?`|[\]])/gu, "\\$1")
+     .replace(/([\t ])/gu, "\\$1");
+ }
+

package.json

@@ -96,7 +96,7 @@
     "prettier": "3.7.3",
     "publint": "0.3.18",
     "rollup": "4.60.0",
-    "shescape-previous": "npm:shescape@2.1.10",
+    "shescape-previous": "npm:shescape@2.1.7",
     "sinon": "21.0.3"
   },
   "scripts": {
@@ -139,7 +139,7 @@
     "mutation:unit": "stryker run config/stryker/unit.js",
     "mutation:integration": "npm run transpile && stryker run config/stryker/integration.js",
     "test": "npm-run-all test:*",
-    "test:unit": "ava test/unit/**/*.test.js",
+    "test:unit": "ava --timeout 59m test/unit/**/*.test.js",
     "test:integration": "npm run transpile && ava test/integration/**/*.test.js --timeout 2m",
     "test:e2e": "node script/busybox-sh.js && node script/double-link-sh.js && ava test/e2e/**/*.test.js --timeout 1m",
     "test:compat": "npm-run-all test:compat:*",

test/unit/unix/bash.test.js

@@ -0,0 +1,55 @@
+/**
+ * @overview Contains (additional) unit tests for the escaping functionality for
+ * the Bourne-again shell (Bash).
+ * @license MIT
+ */
+
+import { testProp } from "@fast-check/ava";
+import * as fc from "fast-check";
+
+import * as old from "../../../node_modules/shescape-previous/src/internal/unix/bash.js";
+import * as upd from "../../../src/internal/unix/bash.js";
+
+const numRuns = 5_000_000;
+
+testProp(
+  "escape functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getEscapeFunction();
+    const oldFn = old.getEscapeFunction();
+
+    const got = updFn(arg).replace(/(?<=[:=])(\\~)(?!\\?[\s+\-/0:=]|$)/gu, "~");
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "quote functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getQuoteFunction();
+    const oldFn = old.getQuoteFunction();
+
+    const got = updFn[0](updFn[1](arg));
+    const want = oldFn[0](oldFn[1](arg));
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "flag protection functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getFlagProtectionFunction();
+    const oldFn = old.getFlagProtectionFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);

test/unit/unix/busybox.test.js

@@ -0,0 +1,55 @@
+/**
+ * @overview Contains (additional) unit tests for the escaping functionality for
+ * the BusyBox shell.
+ * @license MIT
+ */
+
+import { testProp } from "@fast-check/ava";
+import * as fc from "fast-check";
+
+import * as old from "../../../node_modules/shescape-previous/src/internal/unix/busybox.js";
+import * as upd from "../../../src/internal/unix/busybox.js";
+
+const numRuns = 5_000_000;
+
+testProp(
+  "escape functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getEscapeFunction();
+    const oldFn = old.getEscapeFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "quote functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getQuoteFunction();
+    const oldFn = old.getQuoteFunction();
+
+    const got = updFn[0](updFn[1](arg));
+    const want = oldFn[0](oldFn[1](arg));
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "flag protection functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getFlagProtectionFunction();
+    const oldFn = old.getFlagProtectionFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);

test/unit/unix/csh.test.js

@@ -9,10 +9,54 @@ import { TextDecoder } from "node:util";
 import { testProp } from "@fast-check/ava";
 import * as fc from "fast-check";
 
+import * as old from "../../../node_modules/shescape-previous/src/internal/unix/csh.js";
 import * as csh from "../../../src/internal/unix/csh.js";
 
+const numRuns = 5_000_000;
 const textDecoder = new TextDecoder("utf-8", { fatal: true });
 
+testProp(
+  "escape functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = csh.getEscapeFunction();
+    const oldFn = old.getEscapeFunction();
+
+    const got = updFn(arg).replace(/\\!$/gu, "!");
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "quote functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = csh.getQuoteFunction();
+    const oldFn = old.getQuoteFunction();
+
+    const got = updFn[0](updFn[1](arg));
+    const want = oldFn[0](oldFn[1](arg));
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "flag protection functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = csh.getFlagProtectionFunction();
+    const oldFn = old.getFlagProtectionFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
 testProp(
   "characters with 0xA0 when utf-8 encoded",
   [

test/unit/unix/no-shell.test.js

@@ -7,8 +7,39 @@
 import { testProp } from "@fast-check/ava";
 import * as fc from "fast-check";
 
+import * as old from "../../../node_modules/shescape-previous/src/internal/unix/no-shell.js";
 import * as nosh from "../../../src/internal/unix/no-shell.js";
 
+const numRuns = 5_000_000;
+
+testProp(
+  "escape functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = nosh.getEscapeFunction();
+    const oldFn = old.getEscapeFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "flag protection functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = nosh.getFlagProtectionFunction();
+    const oldFn = old.getFlagProtectionFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
 testProp("quote function", [fc.string()], (t, arg) => {
   const expected = {
     instanceOf: Error,

test/unit/win/cmd.test.js

@@ -0,0 +1,55 @@
+/**
+ * @overview Contains (additional) unit tests for the escaping functionality for
+ * the the Windows Command Prompt.
+ * @license MIT
+ */
+
+import { testProp } from "@fast-check/ava";
+import * as fc from "fast-check";
+
+import * as old from "../../../node_modules/shescape-previous/src/internal/win/cmd.js";
+import * as upd from "../../../src/internal/win/cmd.js";
+
+const numRuns = 5_000_000;
+
+testProp(
+  "escape functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getEscapeFunction();
+    const oldFn = old.getEscapeFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "quote functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getQuoteFunction();
+    const oldFn = old.getQuoteFunction();
+
+    const got = updFn[0](updFn[1](arg));
+    const want = oldFn[0](oldFn[1](arg));
+    t.is(got, want);
+  },
+  { numRuns },
+);
+
+testProp(
+  "flag protection functionality is unchanged",
+  [fc.string()],
+  (t, arg) => {
+    const updFn = upd.getFlagProtectionFunction();
+    const oldFn = old.getFlagProtectionFunction();
+
+    const got = updFn(arg);
+    const want = oldFn(arg);
+    t.is(got, want);
+  },
+  { numRuns },
+);