Create breakage tests for the testing modules

Expand the breakage test suite with a test file for the shescape/testing
module. This suite is a bit interesting because it contains some skipped
tests. These tests are skipped because of bugfixes and an API extension
which both occurred in [1].

The breakage coverage configuration is also updated to include the
testing module in the coverage report.

--
1. 4f03fd8

.c8/breakage.json

@@ -1,6 +1,6 @@
 {
   "all": true,
-  "include": ["src/", "index.js"],
+  "include": ["src/", "index.js", "testing.js"],
   "exclude": [],
   "check-coverage": false,
   "reports-dir": "_reports/coverage/breakage",

test/breakage/testing.test.js

@@ -0,0 +1,151 @@
+/**
+ * @overview Contains breakage tests for the shescape testing module.
+ * @license MIT
+ */
+
+import { testProp } from "@fast-check/ava";
+import * as fc from "fast-check";
+
+import { arbitrary } from "./_.js";
+
+import { Shescape as Stubscape, Throwscape } from "shescape/testing";
+import { Shescape as Previoustub } from "shescape-previous/testing";
+
+testProp(
+  "Stubscape#escape",
+  [arbitrary.shescapeOptions(), fc.anything()],
+  (t, options, arg) => {
+    let result, previousResult, errored, previousErrored;
+    let stubscape, previoustub;
+
+    try {
+      stubscape = new Stubscape(options);
+      result = stubscape.escape(arg);
+    } catch (_) {
+      errored = true;
+    }
+
+    try {
+      previoustub = new Previoustub(options);
+      previousResult = previoustub.escape(arg);
+    } catch (_) {
+      previousErrored = true;
+    }
+
+    t.is(errored, previousErrored);
+    t.is(typeof result, typeof previousResult);
+  },
+);
+
+testProp(
+  "Stubscape#escapeAll",
+  [
+    arbitrary.shescapeOptions(),
+    fc.oneof(fc.anything(), fc.array(fc.anything())),
+  ],
+  (t, options, args) => {
+    let result, previousResult, errored, previousErrored;
+    let stubscape, previoustub;
+
+    try {
+      stubscape = new Stubscape(options);
+      result = stubscape.escapeAll(args);
+    } catch (_) {
+      errored = true;
+    }
+
+    try {
+      previoustub = new Previoustub(options);
+      previousResult = previoustub.escapeAll(args);
+    } catch (_) {
+      previousErrored = true;
+    }
+
+    t.is(errored, previousErrored);
+    t.is(typeof result, typeof previousResult);
+  },
+);
+
+// TODO: unskip upon release 2.0.1/2.1.0. It's currently skipped because the
+// implementation was incorrect in 2.0.0 and has been fixed since (in 4f03fd8).
+testProp.skip(
+  "Stubscape#quote",
+  [arbitrary.shescapeOptions(), fc.anything()],
+  (t, options, arg) => {
+    let result, previousResult, errored, previousErrored;
+    let stubscape, previoustub;
+
+    try {
+      stubscape = new Stubscape(options);
+      result = stubscape.quote(arg);
+    } catch (_) {
+      errored = true;
+    }
+
+    try {
+      previoustub = new Previoustub(options);
+      previousResult = previoustub.quote(arg);
+    } catch (_) {
+      previousErrored = true;
+    }
+
+    t.is(errored, previousErrored);
+    t.is(typeof result, typeof previousResult);
+  },
+);
+
+// TODO: unskip upon release 2.0.1/2.1.0. It's currently skipped because the
+// implementation was incorrect in 2.0.0 and has been fixed since (in 4f03fd8).
+testProp.skip(
+  "Stubscape#quoteAll",
+  [
+    arbitrary.shescapeOptions(),
+    fc.oneof(fc.anything(), fc.array(fc.anything())),
+  ],
+  (t, options, args) => {
+    let result, previousResult, errored, previousErrored;
+    let stubscape, previoustub;
+
+    try {
+      stubscape = new Stubscape(options);
+      result = stubscape.quoteAll(args);
+    } catch (_) {
+      errored = true;
+    }
+
+    try {
+      previoustub = new Previoustub(options);
+      previousResult = previoustub.quoteAll(args);
+    } catch (_) {
+      previousErrored = true;
+    }
+
+    t.is(errored, previousErrored);
+    t.is(typeof result, typeof previousResult);
+  },
+);
+
+// TODO: unskip upon release 2.0.1/2.1.0. It's currently skipped because the
+// `Throwscape` class was not yet release in 2.0.0 (added in 4f03fd8).
+testProp.skip(
+  "Throwscape#constructor",
+  [arbitrary.shescapeOptions()],
+  (t, options) => {
+    let errored, previousErrored;
+    let throwscape, previousthrow;
+
+    try {
+      throwscape = new Throwscape(options);
+    } catch (_) {
+      errored = true;
+    }
+
+    try {
+      previousthrow = new Previousthrow(options);
+    } catch (_) {
+      previousErrored = true;
+    }
+
+    t.is(errored, previousErrored);
+  },
+);