Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 830 insertions, 0 deletions

diff --git a/devtools/shared/commands/script/moz.build b/devtools/shared/commands/script/moz.build
new file mode 100644
index 0000000000..2387c7e63b
--- /dev/null
+++ b/devtools/shared/commands/script/moz.build
@@ -0,0 +1,10 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    "script-command.js",
+)
+
+if CONFIG["MOZ_BUILD_APP"] != "mobile/android":
+    BROWSER_CHROME_MANIFESTS += ["tests/browser.ini"]
diff --git a/devtools/shared/commands/script/script-command.js b/devtools/shared/commands/script/script-command.js
new file mode 100644
index 0000000000..93917944d5
--- /dev/null
+++ b/devtools/shared/commands/script/script-command.js
@@ -0,0 +1,149 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+const {
+  getAdHocFrontOrPrimitiveGrip,
+  // eslint-disable-next-line mozilla/reject-some-requires
+} = require("resource://devtools/client/fronts/object.js");
+
+class ScriptCommand {
+  constructor({ commands }) {
+    this._commands = commands;
+  }
+
+  /**
+   * Execute a JavaScript expression.
+   *
+   * @param {String} expression: The code you want to evaluate.
+   * @param {Object} options: Options for evaluation:
+   * @param {Object} options.frameActor: a FrameActor ID. The actor holds a reference to
+   *        a Debugger.Frame. This option allows you to evaluate the string in the frame
+   *        of the given FrameActor.
+   * @param {String} options.url: the url to evaluate the script as. Defaults to "debugger eval code".
+   * @param {TargetFront} options.selectedTargetFront: When passed, the expression will be
+   *        evaluated in the context of the target (as opposed to the default, top-level one).
+   * @param {String} options.selectedNodeActor: A NodeActor ID that may be used by helper
+   *        functions that can reference the currently selected node in the Inspector, like $0.
+   * @param {String} options.selectedObjectActor: the actorID of a given objectActor.
+   *        This is used by context menu entries to get a reference to an object, in order
+   *        to perform some operation on it (copy it, store it as a global variable, …).
+   * @param {Number} options.innerWindowID: An optional window id to be used for the evaluation,
+   *        instead of the regular webConsoleActor.evalWindow.
+   *        This is used by functions that may want to evaluate in a different window (for
+   *        example a non-remote iframe), like getting the elements of a given document.
+   * @param {object} options.mapped: An optional object indicating if the original expression
+   *        entered by the users have been modified
+   * @param {boolean} options.mapped.await: true if the expression was a top-level await
+   *        expression that was wrapped in an async-iife
+   *
+   * @return {Promise}: A promise that resolves with the response.
+   */
+  async execute(expression, options = {}) {
+    const {
+      selectedObjectActor,
+      selectedNodeActor,
+      frameActor,
+      selectedTargetFront,
+    } = options;
+
+    // Retrieve the right WebConsole front that relates either to (by order of priority):
+    // - the currently selected target in the context selector
+    //   (selectedTargetFront argument),
+    // - the object picked in the console (when using store as global) (selectedObjectActor),
+    // - the currently selected Node in the inspector (selectedNodeActor),
+    // - the currently selected frame in the debugger (when paused) (frameActor),
+    // - the currently selected target in the iframe dropdown
+    //   (selectedTargetFront from the TargetCommand)
+    let targetFront = this._commands.targetCommand.selectedTargetFront;
+
+    const selectedActor =
+      selectedObjectActor || selectedNodeActor || frameActor;
+
+    if (selectedTargetFront) {
+      targetFront = selectedTargetFront;
+    } else if (selectedActor) {
+      const selectedFront = this._commands.client.getFrontByID(selectedActor);
+      if (selectedFront) {
+        targetFront = selectedFront.targetFront;
+      }
+    }
+
+    const consoleFront = await targetFront.getFront("console");
+
+    // We call `evaluateJSAsync` RDP request, which immediately returns a simple `resultID`,
+    // for which we later receive a related `evaluationResult` RDP event, with the same resultID.
+    // The evaluation result will be contained in this RDP event.
+    let resultID;
+    const response = await new Promise(resolve => {
+      const offEvaluationResult = consoleFront.on(
+        "evaluationResult",
+        async packet => {
+          // In some cases, the evaluationResult event can be received before the call to
+          // evaluationJSAsync completes. So make sure to wait for the corresponding promise
+          // before handling the evaluationResult event.
+          await onEvaluateJSAsync;
+
+          if (packet.resultID === resultID) {
+            resolve(packet);
+            offEvaluationResult();
+          }
+        }
+      );
+
+      const onEvaluateJSAsync = consoleFront
+        .evaluateJSAsync({
+          text: expression,
+          eager: options.eager,
+          frameActor,
+          innerWindowID: options.innerWindowID,
+          mapped: options.mapped,
+          selectedNodeActor,
+          selectedObjectActor,
+          url: options.url,
+        })
+        .then(packet => {
+          resultID = packet.resultID;
+        });
+    });
+
+    // `response` is the packet sent via `evaluationResult` RDP event.
+    if (response.error) {
+      throw response;
+    }
+
+    if (response.result) {
+      response.result = getAdHocFrontOrPrimitiveGrip(
+        response.result,
+        consoleFront
+      );
+    }
+
+    if (response.helperResult?.object) {
+      response.helperResult.object = getAdHocFrontOrPrimitiveGrip(
+        response.helperResult.object,
+        consoleFront
+      );
+    }
+
+    if (response.exception) {
+      response.exception = getAdHocFrontOrPrimitiveGrip(
+        response.exception,
+        consoleFront
+      );
+    }
+
+    if (response.exceptionMessage) {
+      response.exceptionMessage = getAdHocFrontOrPrimitiveGrip(
+        response.exceptionMessage,
+        consoleFront
+      );
+    }
+
+    return response;
+  }
+}
+
+module.exports = ScriptCommand;
diff --git a/devtools/shared/commands/script/tests/browser.ini b/devtools/shared/commands/script/tests/browser.ini
new file mode 100644
index 0000000000..949c54f760
--- /dev/null
+++ b/devtools/shared/commands/script/tests/browser.ini
@@ -0,0 +1,11 @@
+[DEFAULT]
+tags = devtools
+subsuite = devtools
+support-files =
+  !/devtools/client/shared/test/shared-head.js
+  head.js
+
+[browser_script_command_execute_basic.js]
+[browser_script_command_execute_document__proto__.js]
+[browser_script_command_execute_last_result.js]
+[browser_script_command_execute_throw.js]
diff --git a/devtools/shared/commands/script/tests/browser_script_command_execute_basic.js b/devtools/shared/commands/script/tests/browser_script_command_execute_basic.js
new file mode 100644
index 0000000000..5eff8c4520
--- /dev/null
+++ b/devtools/shared/commands/script/tests/browser_script_command_execute_basic.js
@@ -0,0 +1,413 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Testing basic expression evaluation
+const {
+  MAX_AUTOCOMPLETE_ATTEMPTS,
+  MAX_AUTOCOMPLETIONS,
+} = require("resource://devtools/shared/webconsole/js-property-provider.js");
+const {
+  DevToolsServer,
+} = require("resource://devtools/server/devtools-server.js");
+
+add_task(async () => {
+  const tab = await addTab(`data:text/html;charset=utf-8,
+  <script>
+    window.foobarObject = Object.create(
+      null,
+      Object.getOwnPropertyDescriptors({
+        foo: 1,
+        foobar: 2,
+        foobaz: 3,
+        omg: 4,
+        omgfoo: 5,
+        strfoo: "foobarz",
+        omgstr: "foobarz" + "abb".repeat(${DevToolsServer.LONG_STRING_LENGTH} * 2),
+      })
+    );
+
+    window.largeObject1 = Object.create(null);
+    for (let i = 0; i < ${MAX_AUTOCOMPLETE_ATTEMPTS} + 1; i++) {
+      window.largeObject1["a" + i] = i;
+    }
+
+    window.largeObject2 = Object.create(null);
+    for (let i = 0; i < ${MAX_AUTOCOMPLETIONS} * 2; i++) {
+      window.largeObject2["a" + i] = i;
+    }
+
+    var originalExec = RegExp.prototype.exec;
+
+    var promptIterable = { [Symbol.iterator]() { return { next: prompt } } };
+
+    function aliasedTest() {
+      const aliased = "ALIASED";
+      return [0].map(() => aliased)[0];
+    }
+  </script>`);
+
+  const commands = await CommandsFactory.forTab(tab);
+  await commands.targetCommand.startListening();
+
+  await doSimpleEval(commands);
+  await doWindowEval(commands);
+  await doEvalWithException(commands);
+  await doEvalWithHelper(commands);
+  await doEvalString(commands);
+  await doEvalLongString(commands);
+  await doEvalWithBinding(commands);
+  await forceLexicalInit(commands);
+  await doSimpleEagerEval(commands);
+  await doEagerEvalWithSideEffect(commands);
+  await doEagerEvalWithSideEffectIterator(commands);
+  await doEagerEvalWithSideEffectMonkeyPatched(commands);
+
+  await commands.destroy();
+});
+
+async function doSimpleEval(commands) {
+  info("test eval '2+2'");
+  const response = await commands.scriptCommand.execute("2+2");
+  checkObject(response, {
+    input: "2+2",
+    result: 4,
+  });
+
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+}
+
+async function doWindowEval(commands) {
+  info("test eval 'document'");
+  const response = await commands.scriptCommand.execute("document");
+  checkObject(response, {
+    input: "document",
+    result: {
+      type: "object",
+      class: "HTMLDocument",
+      actor: /[a-z]/,
+    },
+  });
+
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+}
+
+async function doEvalWithException(commands) {
+  info("test eval with exception");
+  const response = await commands.scriptCommand.execute(
+    "window.doTheImpossible()"
+  );
+  checkObject(response, {
+    input: "window.doTheImpossible()",
+    result: {
+      type: "undefined",
+    },
+    exceptionMessage: /doTheImpossible/,
+  });
+
+  ok(response.exception, "js eval exception");
+  ok(!response.helperResult, "no helper result");
+}
+
+async function doEvalWithHelper(commands) {
+  info("test eval with helper");
+  const response = await commands.scriptCommand.execute("clear()");
+  checkObject(response, {
+    input: "clear()",
+    result: {
+      type: "undefined",
+    },
+    helperResult: { type: "clearOutput" },
+  });
+
+  ok(!response.exception, "no eval exception");
+}
+
+async function doEvalString(commands) {
+  const response = await commands.scriptCommand.execute(
+    "window.foobarObject.strfoo"
+  );
+
+  checkObject(response, {
+    input: "window.foobarObject.strfoo",
+    result: "foobarz",
+  });
+}
+
+async function doEvalLongString(commands) {
+  const response = await commands.scriptCommand.execute(
+    "window.foobarObject.omgstr"
+  );
+
+  const str = await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [],
+    function() {
+      return content.wrappedJSObject.foobarObject.omgstr;
+    }
+  );
+
+  const initial = str.substring(0, DevToolsServer.LONG_STRING_INITIAL_LENGTH);
+
+  checkObject(response, {
+    input: "window.foobarObject.omgstr",
+    result: {
+      type: "longString",
+      initial,
+      length: str.length,
+    },
+  });
+}
+
+async function doEvalWithBinding(commands) {
+  const response = await commands.scriptCommand.execute("document;");
+  const documentActor = response.result.actorID;
+
+  info("running a command with _self as document using selectedObjectActor");
+  const selectedObjectSame = await commands.scriptCommand.execute(
+    "_self === document",
+    {
+      selectedObjectActor: documentActor,
+    }
+  );
+  checkObject(selectedObjectSame, {
+    result: true,
+  });
+}
+
+async function forceLexicalInit(commands) {
+  info("test that failed let/const bindings are initialized to undefined");
+
+  const testData = [
+    {
+      stmt: "let foopie = wubbalubadubdub",
+      vars: ["foopie"],
+    },
+    {
+      stmt: "let {z, w={n}=null} = {}",
+      vars: ["z", "w"],
+    },
+    {
+      stmt: "let [a, b, c] = null",
+      vars: ["a", "b", "c"],
+    },
+    {
+      stmt: "const nein1 = rofl, nein2 = copter",
+      vars: ["nein1", "nein2"],
+    },
+    {
+      stmt: "const {ha} = null",
+      vars: ["ha"],
+    },
+    {
+      stmt: "const [haw=[lame]=null] = []",
+      vars: ["haw"],
+    },
+    {
+      stmt: "const [rawr, wat=[lame]=null] = []",
+      vars: ["rawr", "haw"],
+    },
+    {
+      stmt: "let {zzz: xyz=99, zwz: wb} = nexistepas()",
+      vars: ["xyz", "wb"],
+    },
+    {
+      stmt: "let {c3pdoh=101} = null",
+      vars: ["c3pdoh"],
+    },
+    {
+      stmt: "const {...x} = x",
+      vars: ["x"],
+    },
+    {
+      stmt: "const {xx,yy,...rest} = null",
+      vars: ["xx", "yy", "rest"],
+    },
+  ];
+
+  for (const data of testData) {
+    const response = await commands.scriptCommand.execute(data.stmt);
+    checkObject(response, {
+      input: data.stmt,
+      result: { type: "undefined" },
+    });
+    ok(response.exception, "expected exception");
+    for (const varName of data.vars) {
+      const response2 = await commands.scriptCommand.execute(varName);
+      checkObject(response2, {
+        input: varName,
+        result: { type: "undefined" },
+      });
+      ok(!response2.exception, "unexpected exception");
+    }
+  }
+}
+
+async function doSimpleEagerEval(commands) {
+  const testData = [
+    {
+      code: "2+2",
+      result: 4,
+    },
+    {
+      code: "(x => x * 2)(3)",
+      result: 6,
+    },
+    {
+      code: "[1, 2, 3].map(x => x * 2).join()",
+      result: "2,4,6",
+    },
+    {
+      code: `"abc".match(/a./)[0]`,
+      result: "ab",
+    },
+    {
+      code: "aliasedTest()",
+      result: "ALIASED",
+    },
+  ];
+
+  for (const { code, result } of testData) {
+    const response = await commands.scriptCommand.execute(code, {
+      eager: true,
+    });
+    checkObject(response, {
+      input: code,
+      result,
+    });
+
+    ok(!response.exception, "no eval exception");
+    ok(!response.helperResult, "no helper result");
+  }
+}
+
+async function doEagerEvalWithSideEffect(commands) {
+  const testData = [
+    // Modify environment.
+    "var a = 10; a;",
+
+    // Directly call a funtion with side effect.
+    "prompt();",
+
+    // Call a funtion with side effect inside a scripted function.
+    "(() => { prompt(); })()",
+
+    // Call a funtion with side effect from self-hosted JS function.
+    "[1, 2, 3].map(prompt)",
+
+    // Call a function with Function.prototype.call.
+    "Function.prototype.call.bind(Function.prototype.call)(prompt);",
+
+    // Call a function with Function.prototype.apply.
+    "Function.prototype.apply.bind(Function.prototype.apply)(prompt);",
+
+    // Indirectly call a function with Function.prototype.apply.
+    "Reflect.apply(prompt, null, []);",
+    "'aaaaaaaa'.replace(/(a)(a)(a)(a)(a)(a)(a)(a)/, prompt)",
+
+    // Indirect call on obj[Symbol.iterator]().next.
+    "Array.from(promptIterable)",
+  ];
+
+  for (const code of testData) {
+    const response = await commands.scriptCommand.execute(code, {
+      eager: true,
+    });
+    checkObject(response, {
+      input: code,
+      result: { type: "undefined" },
+    });
+
+    ok(!response.exception, "no eval exception");
+    ok(!response.helperResult, "no helper result");
+  }
+}
+
+async function doEagerEvalWithSideEffectIterator(commands) {
+  // Indirect call on %ArrayIterator%.prototype.next,
+
+  // Create an iterable object that reuses iterator across multiple call.
+  let response = await commands.scriptCommand.execute(`
+var arr = [1, 2, 3];
+var iterator = arr[Symbol.iterator]();
+var iterable = { [Symbol.iterator]() { return iterator; } };
+"ok";
+`);
+  checkObject(response, {
+    result: "ok",
+  });
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+
+  const testData = [
+    "Array.from(iterable)",
+    "new Map(iterable)",
+    "new Set(iterable)",
+  ];
+
+  for (const code of testData) {
+    response = await commands.scriptCommand.execute(code, {
+      eager: true,
+    });
+    checkObject(response, {
+      input: code,
+      result: { type: "undefined" },
+    });
+
+    ok(!response.exception, "no eval exception");
+    ok(!response.helperResult, "no helper result");
+  }
+
+  // Verify the iterator's internal state isn't modified.
+  response = await commands.scriptCommand.execute(`[...iterator].join(",")`);
+  checkObject(response, {
+    result: "1,2,3",
+  });
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+}
+
+async function doEagerEvalWithSideEffectMonkeyPatched(commands) {
+  // Patch the built-in function without eager evaluation.
+  let response = await commands.scriptCommand.execute(
+    `RegExp.prototype.exec = prompt; "patched"`
+  );
+  checkObject(response, {
+    result: "patched",
+  });
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+
+  // Test eager evaluation, where the patched built-in is called internally.
+  // This should be aborted.
+  const code = `"abc".match(/a./)[0]`;
+  response = await commands.scriptCommand.execute(code, { eager: true });
+  checkObject(response, {
+    input: code,
+    result: { type: "undefined" },
+  });
+
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+
+  // Undo the patch without eager evaluation.
+  response = await commands.scriptCommand.execute(
+    `RegExp.prototype.exec = originalExec; "unpatched"`
+  );
+  checkObject(response, {
+    result: "unpatched",
+  });
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+
+  // Test eager evaluation again, without the patch.
+  // This should be evaluated.
+  response = await commands.scriptCommand.execute(code, { eager: true });
+  checkObject(response, {
+    input: code,
+    result: "ab",
+  });
+}
diff --git a/devtools/shared/commands/script/tests/browser_script_command_execute_document__proto__.js b/devtools/shared/commands/script/tests/browser_script_command_execute_document__proto__.js
new file mode 100644
index 0000000000..28f56ebac3
--- /dev/null
+++ b/devtools/shared/commands/script/tests/browser_script_command_execute_document__proto__.js
@@ -0,0 +1,41 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Testing evaluating document.__proto__
+
+add_task(async () => {
+  const tab = await addTab(
+    `data:text/html;charset=utf-8,Test evaluating document.__proto__`
+  );
+  const commands = await CommandsFactory.forTab(tab);
+  await commands.targetCommand.startListening();
+
+  const evaluationResponse = await commands.scriptCommand.execute(
+    "document.__proto__"
+  );
+  checkObject(evaluationResponse, {
+    input: "document.__proto__",
+    result: {
+      type: "object",
+      actor: /[a-z]/,
+    },
+  });
+
+  ok(!evaluationResponse.exception, "no eval exception");
+  ok(!evaluationResponse.helperResult, "no helper result");
+
+  const response = await evaluationResponse.result.getPrototypeAndProperties();
+  ok(!response.error, "no response error");
+
+  const props = response.ownProperties;
+  ok(props, "response properties available");
+
+  const expectedProps = Object.getOwnPropertyNames(
+    Object.getPrototypeOf(document)
+  );
+  checkObject(Object.keys(props), expectedProps, "Same own properties.");
+
+  await commands.destroy();
+});
diff --git a/devtools/shared/commands/script/tests/browser_script_command_execute_last_result.js b/devtools/shared/commands/script/tests/browser_script_command_execute_last_result.js
new file mode 100644
index 0000000000..aebdaeb168
--- /dev/null
+++ b/devtools/shared/commands/script/tests/browser_script_command_execute_last_result.js
@@ -0,0 +1,85 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Testing that last evaluation result can be accessed with `$_`
+
+add_task(async () => {
+  const tab = await addTab(`data:text/html;charset=utf-8,`);
+
+  const commands = await CommandsFactory.forTab(tab);
+  await commands.targetCommand.startListening();
+
+  info("$_ returns undefined if nothing has evaluated yet");
+  let response = await commands.scriptCommand.execute("$_");
+  basicResultCheck(response, "$_", { type: "undefined" });
+
+  info("$_ returns last value and performs basic arithmetic");
+  response = await commands.scriptCommand.execute("2+2");
+  basicResultCheck(response, "2+2", 4);
+
+  response = await commands.scriptCommand.execute("$_");
+  basicResultCheck(response, "$_", 4);
+
+  response = await commands.scriptCommand.execute("$_ + 2");
+  basicResultCheck(response, "$_ + 2", 6);
+
+  response = await commands.scriptCommand.execute("$_ + 4");
+  basicResultCheck(response, "$_ + 4", 10);
+
+  info("$_ has correct references to objects");
+  response = await commands.scriptCommand.execute("var foo = {bar:1}; foo;");
+  basicResultCheck(response, "var foo = {bar:1}; foo;", {
+    type: "object",
+    class: "Object",
+    actor: /[a-z]/,
+  });
+  checkObject(response.result.getGrip().preview.ownProperties, {
+    bar: {
+      value: 1,
+    },
+  });
+
+  response = await commands.scriptCommand.execute("$_");
+  basicResultCheck(response, "$_", {
+    type: "object",
+    class: "Object",
+    actor: /[a-z]/,
+  });
+  checkObject(response.result.getGrip().preview.ownProperties, {
+    bar: {
+      value: 1,
+    },
+  });
+
+  info(
+    "Update a property value and check that evaluating $_ returns the expected object instance"
+  );
+  await ContentTask.spawn(gBrowser.selectedBrowser, null, () => {
+    content.wrappedJSObject.foo.bar = "updated_value";
+  });
+
+  response = await commands.scriptCommand.execute("$_");
+  basicResultCheck(response, "$_", {
+    type: "object",
+    class: "Object",
+    actor: /[a-z]/,
+  });
+  checkObject(response.result.getGrip().preview.ownProperties, {
+    bar: {
+      value: "updated_value",
+    },
+  });
+
+  await commands.destroy();
+});
+
+function basicResultCheck(response, input, output) {
+  checkObject(response, {
+    input,
+    result: output,
+  });
+  ok(!response.exception, "no eval exception");
+  ok(!response.helperResult, "no helper result");
+}
diff --git a/devtools/shared/commands/script/tests/browser_script_command_execute_throw.js b/devtools/shared/commands/script/tests/browser_script_command_execute_throw.js
new file mode 100644
index 0000000000..8680193ecb
--- /dev/null
+++ b/devtools/shared/commands/script/tests/browser_script_command_execute_throw.js
@@ -0,0 +1,75 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Testing evaluating thowing expressions
+const {
+  DevToolsServer,
+} = require("resource://devtools/server/devtools-server.js");
+
+add_task(async () => {
+  const tab = await addTab(`data:text/html;charset=utf-8,Test throw`);
+  const commands = await CommandsFactory.forTab(tab);
+  await commands.targetCommand.startListening();
+
+  const falsyValues = [
+    "-0",
+    "null",
+    "undefined",
+    "Infinity",
+    "-Infinity",
+    "NaN",
+  ];
+  for (const value of falsyValues) {
+    const response = await commands.scriptCommand.execute(`throw ${value};`);
+    is(
+      response.exception.type,
+      value,
+      `Got the expected value for response.exception.type when throwing "${value}"`
+    );
+  }
+
+  const identityTestValues = [false, 0];
+  for (const value of identityTestValues) {
+    const response = await commands.scriptCommand.execute(`throw ${value};`);
+    is(
+      response.exception,
+      value,
+      `Got the expected value for response.exception when throwing "${value}"`
+    );
+  }
+
+  const symbolTestValues = [
+    ["Symbol.iterator", "Symbol(Symbol.iterator)"],
+    ["Symbol('foo')", "Symbol(foo)"],
+    ["Symbol()", "Symbol()"],
+  ];
+  for (const [expr, message] of symbolTestValues) {
+    const response = await commands.scriptCommand.execute(`throw ${expr};`);
+    is(
+      response.exceptionMessage,
+      message,
+      `Got the expected value for response.exceptionMessage when throwing "${expr}"`
+    );
+  }
+
+  const longString = Array(DevToolsServer.LONG_STRING_LENGTH + 1).join("a"),
+    shortedString = longString.substring(
+      0,
+      DevToolsServer.LONG_STRING_INITIAL_LENGTH
+    );
+  const response = await commands.scriptCommand.execute(
+    "throw '" + longString + "';"
+  );
+  is(
+    response.exception.initial,
+    shortedString,
+    "Got the expected value for exception.initial when throwing a longString"
+  );
+  is(
+    response.exceptionMessage.initial,
+    shortedString,
+    "Got the expected value for exceptionMessage.initial when throwing a longString"
+  );
+});
diff --git a/devtools/shared/commands/script/tests/head.js b/devtools/shared/commands/script/tests/head.js
new file mode 100644
index 0000000000..9b7591a9cf
--- /dev/null
+++ b/devtools/shared/commands/script/tests/head.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* import-globals-from ../../../../client/shared/test/shared-head.js */
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/devtools/client/shared/test/shared-head.js",
+  this
+);
+
+function checkObject(object, expected) {
+  if (object && object.getGrip) {
+    object = object.getGrip();
+  }
+
+  for (const name of Object.keys(expected)) {
+    const expectedValue = expected[name];
+    const value = object[name];
+    checkValue(name, value, expectedValue);
+  }
+}
+
+function checkValue(name, value, expected) {
+  if (expected === null) {
+    is(value, null, `'${name}' is null`);
+  } else if (expected === undefined) {
+    is(value, expected, `'${name}' is undefined`);
+  } else if (
+    typeof expected == "string" ||
+    typeof expected == "number" ||
+    typeof expected == "boolean"
+  ) {
+    is(value, expected, "property '" + name + "'");
+  } else if (expected instanceof RegExp) {
+    ok(expected.test(value), name + ": " + expected + " matched " + value);
+  } else if (Array.isArray(expected)) {
+    info("checking array for property '" + name + "'");
+    checkObject(value, expected);
+  } else if (typeof expected == "object") {
+    info("checking object for property '" + name + "'");
+    checkObject(value, expected);
+  }
+}