script/dom/
console.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::convert::TryFrom;
6use std::ptr::{self, NonNull};
7use std::slice;
8
9use devtools_traits::{
10    ConsoleLogLevel, ConsoleMessage, ConsoleMessageFields, DebuggerValue, FunctionPreview,
11    ObjectPreview, PropertyDescriptor as DevtoolsPropertyDescriptor, ScriptToDevtoolsControlMsg,
12    StackFrame, get_time_stamp,
13};
14use embedder_traits::EmbedderMsg;
15use js::context::JSContext;
16use js::conversions::jsstr_to_string;
17use js::jsapi::{self, ESClass, JS_GetFunctionArity, PropertyDescriptor, SavedFrameSelfHosted};
18use js::jsval::{Int32Value, UndefinedValue};
19use js::realm::CurrentRealm;
20use js::rust::wrappers2::{
21    GetArrayLength, GetBuiltinClass, GetPropertyKeys, GetSavedFrameColumn,
22    GetSavedFrameFunctionDisplayName, GetSavedFrameLine, GetSavedFrameSource,
23    JS_ClearPendingException, JS_GetElement, JS_GetFunctionDisplayId, JS_GetFunctionId,
24    JS_GetOwnPropertyDescriptorById, JS_GetPropertyById, JS_IdToValue, JS_Stringify,
25    JS_ValueToFunction, JS_ValueToSource, MapEntries, MapSize,
26};
27use js::rust::{
28    CapturedJSStack, HandleObject, HandleValue, IdVector, ToNumber, ToString,
29    describe_scripted_caller_safe, for_of,
30};
31use script_bindings::conversions::get_dom_class;
32
33use crate::dom::bindings::codegen::Bindings::ConsoleBinding::consoleMethods;
34use crate::dom::bindings::error::report_pending_exception;
35use crate::dom::bindings::inheritance::Castable;
36use crate::dom::bindings::str::DOMString;
37use crate::dom::globalscope::GlobalScope;
38use crate::dom::workerglobalscope::WorkerGlobalScope;
39
40/// The maximum object depth logged by console methods.
41const MAX_LOG_DEPTH: usize = 10;
42/// The maximum elements in an object logged by console methods.
43const MAX_LOG_CHILDREN: usize = 15;
44
45/// <https://developer.mozilla.org/en-US/docs/Web/API/Console>
46#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
47pub(crate) struct Console;
48
49impl Console {
50    fn build_message(
51        cx: &mut JSContext,
52        level: ConsoleLogLevel,
53        arguments: Vec<DebuggerValue>,
54        stacktrace: Option<Vec<StackFrame>>,
55    ) -> ConsoleMessage {
56        let caller = describe_scripted_caller_safe(cx).unwrap_or_default();
57
58        ConsoleMessage {
59            fields: ConsoleMessageFields {
60                level,
61                filename: caller.filename,
62                line_number: caller.line,
63                column_number: caller.col,
64                time_stamp: get_time_stamp(),
65            },
66            arguments,
67            stacktrace,
68        }
69    }
70
71    /// Helper to send a message that only consists of a single string
72    fn send_string_message(
73        cx: &mut JSContext,
74        global: &GlobalScope,
75        level: ConsoleLogLevel,
76        message: String,
77    ) {
78        let prefix = global.current_group_label().unwrap_or_default();
79        let formatted_message = format!("{prefix}{message}");
80
81        Self::send_to_embedder(global, level.clone(), formatted_message);
82
83        let console_message =
84            Self::build_message(cx, level, vec![DebuggerValue::StringValue(message)], None);
85
86        Self::send_to_devtools(global, console_message);
87    }
88
89    fn method(
90        cx: &mut JSContext,
91        global: &GlobalScope,
92        level: ConsoleLogLevel,
93        messages: Vec<HandleValue>,
94        include_stacktrace: IncludeStackTrace,
95    ) {
96        // If the first argument is a string, apply sprintf-style substitutions per the
97        // WHATWG Console spec formatter. The result is a single formatted string followed
98        // by any arguments that were not consumed by a substitution specifier.
99        let (arguments, embedder_msg) = if !messages.is_empty() && messages[0].is_string() {
100            let (formatted, consumed) = apply_sprintf_substitutions(cx, &messages);
101            let remaining = &messages[consumed..];
102
103            let mut arguments: Vec<DebuggerValue> =
104                vec![DebuggerValue::StringValue(formatted.clone())];
105            for msg in remaining {
106                arguments.push(console_argument_from_handle_value(
107                    cx,
108                    *msg,
109                    &mut Vec::new(),
110                ));
111            }
112
113            let embedder_msg = if remaining.is_empty() {
114                formatted
115            } else {
116                format!("{formatted} {}", stringify_handle_values(cx, remaining))
117            };
118
119            (arguments, embedder_msg.into())
120        } else {
121            let arguments = messages
122                .iter()
123                .map(|msg| console_argument_from_handle_value(cx, *msg, &mut Vec::new()))
124                .collect();
125            (arguments, stringify_handle_values(cx, &messages))
126        };
127
128        let stacktrace = (include_stacktrace == IncludeStackTrace::Yes).then_some(get_js_stack(cx));
129        let console_message = Self::build_message(cx, level.clone(), arguments, stacktrace);
130
131        Console::send_to_devtools(global, console_message);
132
133        let prefix = global.current_group_label().unwrap_or_default();
134        let formatted_message = format!("{prefix}{embedder_msg}");
135
136        Self::send_to_embedder(global, level, formatted_message);
137    }
138
139    fn send_to_devtools(global: &GlobalScope, message: ConsoleMessage) {
140        if let Some(chan) = global.devtools_chan() {
141            let worker_id = global
142                .downcast::<WorkerGlobalScope>()
143                .map(|worker| worker.worker_id());
144            let devtools_message =
145                ScriptToDevtoolsControlMsg::ConsoleAPI(global.pipeline_id(), message, worker_id);
146            chan.send(devtools_message).unwrap();
147        }
148    }
149
150    fn send_to_embedder(global: &GlobalScope, level: ConsoleLogLevel, message: String) {
151        global.send_to_embedder(EmbedderMsg::ShowConsoleApiMessage(
152            global.webview_id(),
153            level,
154            message,
155        ));
156    }
157
158    // Directly logs a string message, without processing the message
159    pub(crate) fn internal_warn(cx: &mut JSContext, global: &GlobalScope, message: String) {
160        Console::send_string_message(cx, global, ConsoleLogLevel::Warn, message);
161    }
162}
163
164#[expect(unsafe_code)]
165fn handle_value_to_string(cx: &mut JSContext, value: HandleValue) -> DOMString {
166    match std::ptr::NonNull::new(unsafe { JS_ValueToSource(cx, value) }) {
167        Some(js_str) => unsafe { jsstr_to_string(cx, js_str) }.into(),
168        None => "<error converting value to string>".into(),
169    }
170}
171
172fn console_argument_from_handle_value(
173    cx: &mut JSContext,
174    handle_value: HandleValue,
175    seen: &mut Vec<u64>,
176) -> DebuggerValue {
177    #[expect(unsafe_code)]
178    fn inner(
179        cx: &mut JSContext,
180        handle_value: HandleValue,
181        seen: &mut Vec<u64>,
182    ) -> Result<DebuggerValue, ()> {
183        if handle_value.is_string() {
184            let js_string = ptr::NonNull::new(handle_value.to_string()).unwrap();
185            let dom_string = unsafe { jsstr_to_string(cx, js_string) };
186            return Ok(DebuggerValue::StringValue(dom_string));
187        }
188
189        if handle_value.is_number() {
190            let number = handle_value.to_number();
191            return Ok(DebuggerValue::NumberValue(number));
192        }
193
194        if handle_value.is_boolean() {
195            let boolean = handle_value.to_boolean();
196            return Ok(DebuggerValue::BooleanValue(boolean));
197        }
198
199        if handle_value.is_object() {
200            // JS objects can create circular reference, and we want to avoid recursing infinitely
201            if seen.contains(&handle_value.asBits_) {
202                // FIXME: Handle this properly
203                return Ok(DebuggerValue::StringValue("[circular]".into()));
204            }
205
206            seen.push(handle_value.asBits_);
207            let console_object = console_object_from_handle_value(cx, handle_value, seen);
208            let js_value = seen.pop();
209            debug_assert_eq!(js_value, Some(handle_value.asBits_));
210
211            if let Some((class, preview)) = console_object {
212                return Ok(DebuggerValue::ObjectValue {
213                    actor: None,
214                    class,
215                    own_property_length: preview.own_properties_length,
216                    preview: Some(Box::new(preview)),
217                });
218            }
219
220            return Err(());
221        }
222
223        // FIXME: Handle more complex argument types here
224        let stringified_value = stringify_handle_value(cx, handle_value);
225
226        Ok(DebuggerValue::StringValue(stringified_value.into()))
227    }
228
229    match inner(cx, handle_value, seen) {
230        Ok(arg) => arg,
231        Err(()) => {
232            report_pending_exception(&mut CurrentRealm::assert(cx));
233            DebuggerValue::StringValue("<error>".into())
234        },
235    }
236}
237
238fn accessor_value_from_property_descriptor(descriptor: &PropertyDescriptor) -> DebuggerValue {
239    // https://console.spec.whatwg.org/#printer
240    // Objects with either generic JavaScript object formatting or optimally useful formatting applied.
241    let value = match (
242        descriptor.hasGetter_() && !descriptor.getter_.is_null(),
243        descriptor.hasSetter_() && !descriptor.setter_.is_null(),
244    ) {
245        (true, true) => "Getter/Setter",
246        (true, false) => "Getter",
247        (false, true) => "Setter",
248        (false, false) => "undefined",
249    };
250    DebuggerValue::StringValue(value.into())
251}
252
253#[expect(unsafe_code)]
254fn console_map_object_from_handle_value(
255    cx: &mut JSContext,
256    handle_object: HandleObject,
257    seen: &mut Vec<u64>,
258) -> Option<(String, ObjectPreview)> {
259    rooted!(&in(cx) let mut iterator = UndefinedValue());
260    if !unsafe { MapEntries(cx, handle_object, iterator.handle_mut()) } {
261        return None;
262    }
263
264    let mut entries = Vec::new();
265    for_of(unsafe { cx.raw_cx() }, iterator.handle(), |entry| {
266        if !entry.is_object() {
267            return Err(().into());
268        }
269
270        rooted!(&in(cx) let entry_object = entry.to_object());
271        rooted!(&in(cx) let mut key = UndefinedValue());
272        rooted!(&in(cx) let mut value = UndefinedValue());
273
274        // Each map entry is a [key, value] pair.
275        if !unsafe { JS_GetElement(cx, entry_object.handle(), 0, key.handle_mut()) } ||
276            !unsafe { JS_GetElement(cx, entry_object.handle(), 1, value.handle_mut()) }
277        {
278            return Err(().into());
279        }
280
281        entries.push((
282            console_argument_from_handle_value(cx, key.handle(), seen),
283            console_argument_from_handle_value(cx, value.handle(), seen),
284        ));
285
286        Ok(std::ops::ControlFlow::Continue(()))
287    })
288    .ok()?;
289
290    Some((
291        "Map".into(),
292        ObjectPreview {
293            kind: "MapLike".into(),
294            size: Some(unsafe { MapSize(cx, handle_object) }),
295            entries: Some(entries),
296            own_properties_length: Some(0),
297            own_properties: None,
298            function: None,
299            array_length: None,
300            items: None,
301        },
302    ))
303}
304
305#[expect(unsafe_code)]
306fn console_object_from_handle_value(
307    cx: &mut JSContext,
308    handle_value: HandleValue,
309    seen: &mut Vec<u64>,
310) -> Option<(String, ObjectPreview)> {
311    rooted!(&in(cx) let object = handle_value.to_object());
312    let mut object_class = ESClass::Other;
313    if !unsafe { GetBuiltinClass(cx, object.handle(), &mut object_class as *mut _) } {
314        return None;
315    }
316    if object_class != ESClass::Object &&
317        object_class != ESClass::Array &&
318        object_class != ESClass::Map &&
319        object_class != ESClass::Function
320    {
321        return None;
322    }
323
324    if object_class == ESClass::Map {
325        return console_map_object_from_handle_value(cx, object.handle(), seen);
326    }
327
328    let mut own_properties = Vec::new();
329    let mut items: Vec<(i32, DebuggerValue)> = Vec::new();
330    let mut ids = unsafe { IdVector::new(cx.raw_cx()) };
331    // https://console.spec.whatwg.org/#printer
332    // Objects with either generic JavaScript object formatting or optimally useful formatting applied.
333    if !unsafe {
334        GetPropertyKeys(
335            cx,
336            object.handle(),
337            jsapi::JSITER_OWNONLY | jsapi::JSITER_SYMBOLS | jsapi::JSITER_HIDDEN,
338            ids.handle_mut(),
339        )
340    } {
341        return None;
342    }
343
344    for id in ids.iter() {
345        rooted!(&in(cx) let id = *id);
346        rooted!(&in(cx) let mut descriptor = PropertyDescriptor::default());
347
348        let mut is_none = false;
349        if !unsafe {
350            JS_GetOwnPropertyDescriptorById(
351                cx,
352                object.handle(),
353                id.handle(),
354                descriptor.handle_mut(),
355                &mut is_none,
356            )
357        } {
358            return None;
359        }
360        if is_none {
361            continue;
362        }
363
364        // https://console.spec.whatwg.org/#printer
365        // Objects with either generic JavaScript object formatting or optimally useful formatting applied.
366        let is_accessor = (descriptor.hasGetter_() && !descriptor.getter_.is_null()) ||
367            (descriptor.hasSetter_() && !descriptor.setter_.is_null());
368        let value = if is_accessor {
369            accessor_value_from_property_descriptor(&descriptor)
370        } else {
371            rooted!(&in(cx) let property = descriptor.value_);
372            console_argument_from_handle_value(cx, property.handle(), seen)
373        };
374
375        if object_class == ESClass::Array && id.is_int() {
376            let index = id.to_int();
377            items.push((index, value));
378            continue;
379        }
380
381        let key = if id.is_string() {
382            rooted!(&in(cx) let mut key_value = UndefinedValue());
383            if !unsafe { JS_IdToValue(cx, id.handle().get(), key_value.handle_mut()) } {
384                continue;
385            }
386            rooted!(&in(cx) let js_string = key_value.to_string());
387            let Some(js_string) = NonNull::new(js_string.get()) else {
388                continue;
389            };
390            unsafe { jsstr_to_string(cx, js_string) }
391        } else if id.is_symbol() || id.is_int() {
392            rooted!(&in(cx) let mut key_value = UndefinedValue());
393            if !unsafe { JS_IdToValue(cx, id.handle().get(), key_value.handle_mut()) } {
394                continue;
395            }
396            handle_value_to_string(cx, key_value.handle()).to_string()
397        } else {
398            continue;
399        };
400
401        own_properties.push(DevtoolsPropertyDescriptor {
402            name: key,
403            value,
404            configurable: descriptor.hasConfigurable_() && descriptor.configurable_(),
405            enumerable: descriptor.hasEnumerable_() && descriptor.enumerable_(),
406            writable: !is_accessor && descriptor.hasWritable_() && descriptor.writable_(),
407            is_accessor,
408        });
409    }
410
411    let (class, kind, function, array_length, items) = match object_class {
412        ESClass::Array => {
413            let mut len = 0u32;
414            if !unsafe { GetArrayLength(cx, object.handle(), &mut len) } {
415                return None;
416            }
417            items.sort_by_key(|(index, _)| *index);
418            let ordered: Vec<DebuggerValue> = items.into_iter().map(|(_, value)| value).collect();
419            (
420                "Array".into(),
421                "ArrayLike".into(),
422                None,
423                Some(len),
424                Some(ordered),
425            )
426        },
427        ESClass::Function => {
428            rooted!(&in(cx) let fun = unsafe { JS_ValueToFunction(cx, handle_value) });
429            rooted!(&in(cx) let mut name = std::ptr::null_mut::<jsapi::JSString>());
430            rooted!(&in(cx) let mut display_name = std::ptr::null_mut::<jsapi::JSString>());
431            let arity;
432            unsafe {
433                JS_GetFunctionId(cx, fun.handle(), name.handle_mut());
434                JS_GetFunctionDisplayId(cx, fun.handle(), display_name.handle_mut());
435                arity = JS_GetFunctionArity(fun.get());
436            }
437            let name = ptr::NonNull::new(*name).map(|name| unsafe { jsstr_to_string(cx, name) });
438            let display_name = ptr::NonNull::new(*display_name)
439                .map(|display_name| unsafe { jsstr_to_string(cx, display_name) });
440
441            // TODO: We should get the actual argument names from the function
442            // It's not trivial since we can't access the debugger API here
443            let parameter_names = (0..arity).map(|i| format!("<arg{i}>")).collect();
444
445            let function = FunctionPreview {
446                name,
447                display_name,
448                parameter_names,
449                is_async: None,
450                is_generator: None,
451            };
452            (
453                "Function".into(),
454                "Object".into(),
455                Some(function),
456                None,
457                None,
458            )
459        },
460        // TODO: Investigate if this class should be the object class
461        _ => ("Object".into(), "Object".into(), None, None, None),
462    };
463
464    Some((
465        class,
466        ObjectPreview {
467            kind,
468            size: None,
469            entries: None,
470            own_properties_length: Some(own_properties.len() as u32),
471            own_properties: Some(own_properties),
472            function,
473            array_length,
474            items,
475        },
476    ))
477}
478
479#[expect(unsafe_code)]
480pub(crate) fn stringify_handle_value(cx: &mut JSContext, message: HandleValue) -> DOMString {
481    if message.is_string() {
482        let jsstr = std::ptr::NonNull::new(message.to_string()).unwrap();
483        return unsafe { jsstr_to_string(cx, jsstr) }.into();
484    }
485    fn stringify_object_from_handle_value(
486        cx: &mut JSContext,
487        value: HandleValue,
488        parents: Vec<u64>,
489    ) -> DOMString {
490        rooted!(&in(cx) let mut obj = value.to_object());
491        let mut object_class = ESClass::Other;
492        if !unsafe { GetBuiltinClass(cx, obj.handle(), &mut object_class as *mut _) } {
493            return DOMString::from("/* invalid */");
494        }
495        let mut ids = unsafe { IdVector::new(cx.raw_cx()) };
496        if !unsafe {
497            GetPropertyKeys(
498                cx,
499                obj.handle(),
500                jsapi::JSITER_OWNONLY | jsapi::JSITER_SYMBOLS,
501                ids.handle_mut(),
502            )
503        } {
504            return DOMString::from("/* invalid */");
505        }
506        let truncate = ids.len() > MAX_LOG_CHILDREN;
507        if object_class != ESClass::Array && object_class != ESClass::Object {
508            if truncate {
509                return DOMString::from("…");
510            } else {
511                return handle_value_to_string(cx, value);
512            }
513        }
514
515        let mut explicit_keys = object_class == ESClass::Object;
516        let mut props = Vec::with_capacity(ids.len());
517        for id in ids.iter().take(MAX_LOG_CHILDREN) {
518            rooted!(&in(cx) let id = *id);
519            rooted!(&in(cx) let mut desc = PropertyDescriptor::default());
520
521            let mut is_none = false;
522            if !unsafe {
523                JS_GetOwnPropertyDescriptorById(
524                    cx,
525                    obj.handle(),
526                    id.handle(),
527                    desc.handle_mut(),
528                    &mut is_none,
529                )
530            } {
531                return DOMString::from("/* invalid */");
532            }
533
534            rooted!(&in(cx) let mut property = UndefinedValue());
535            if !unsafe { JS_GetPropertyById(cx, obj.handle(), id.handle(), property.handle_mut()) }
536            {
537                return DOMString::from("/* invalid */");
538            }
539
540            if !explicit_keys {
541                if id.is_int() {
542                    if let Ok(id_int) = usize::try_from(id.to_int()) {
543                        explicit_keys = props.len() != id_int;
544                    } else {
545                        explicit_keys = false;
546                    }
547                } else {
548                    explicit_keys = false;
549                }
550            }
551            let value_string = stringify_inner(cx, property.handle(), parents.clone());
552            if explicit_keys {
553                let key = if id.is_string() || id.is_symbol() || id.is_int() {
554                    rooted!(&in(cx) let mut key_value = UndefinedValue());
555                    if !unsafe { JS_IdToValue(cx, id.handle().get(), key_value.handle_mut()) } {
556                        return DOMString::from("/* invalid */");
557                    }
558                    handle_value_to_string(cx, key_value.handle())
559                } else {
560                    return DOMString::from("/* invalid */");
561                };
562                props.push(format!("{}: {}", key, value_string,));
563            } else {
564                props.push(String::from(value_string));
565            }
566        }
567        if truncate {
568            props.push("…".to_string());
569        }
570        if object_class == ESClass::Array {
571            DOMString::from(format!("[{}]", itertools::join(props, ", ")))
572        } else {
573            DOMString::from(format!("{{{}}}", itertools::join(props, ", ")))
574        }
575    }
576    fn stringify_inner(cx: &mut JSContext, value: HandleValue, mut parents: Vec<u64>) -> DOMString {
577        if parents.len() >= MAX_LOG_DEPTH {
578            return DOMString::from("...");
579        }
580        let value_bits = value.asBits_;
581        if parents.contains(&value_bits) {
582            return DOMString::from("[circular]");
583        }
584        if value.is_undefined() {
585            // This produces a better value than "(void 0)" from JS_ValueToSource.
586            return DOMString::from("undefined");
587        } else if !value.is_object() {
588            return handle_value_to_string(cx, value);
589        }
590        parents.push(value_bits);
591
592        if value.is_object() &&
593            let Some(repr) = maybe_stringify_dom_object(cx, value)
594        {
595            return repr;
596        }
597        stringify_object_from_handle_value(cx, value, parents)
598    }
599    stringify_inner(cx, message, Vec::new())
600}
601
602#[expect(unsafe_code)]
603fn maybe_stringify_dom_object(cx: &mut JSContext, value: HandleValue) -> Option<DOMString> {
604    // The standard object serialization is not effective for DOM objects,
605    // since their properties generally live on the prototype object.
606    // Instead, fall back to the output of JSON.stringify combined
607    // with the class name extracted from the output of toString().
608    rooted!(&in(cx) let obj = value.to_object());
609    let is_dom_class = unsafe { get_dom_class(obj.get()).is_ok() };
610    if !is_dom_class {
611        return None;
612    }
613    rooted!(&in(cx) let class_name = unsafe { ToString(cx, value) });
614    let Some(class_name) = NonNull::new(class_name.get()) else {
615        return Some("<error converting DOM object to string>".into());
616    };
617    let class_name = unsafe { jsstr_to_string(cx, class_name) }
618        .replace("[object ", "")
619        .replace("]", "");
620    let mut repr = format!("{} ", class_name);
621    rooted!(&in(cx) let mut value = value.get());
622
623    #[expect(unsafe_code)]
624    unsafe extern "C" fn stringified(
625        string: *const u16,
626        len: u32,
627        data: *mut std::ffi::c_void,
628    ) -> bool {
629        let s = data as *mut String;
630        let string_chars = unsafe { slice::from_raw_parts(string, len as usize) };
631        unsafe { (*s).push_str(&String::from_utf16_lossy(string_chars)) };
632        true
633    }
634
635    rooted!(&in(cx) let space = Int32Value(2));
636    let stringify_result = unsafe {
637        JS_Stringify(
638            cx,
639            value.handle_mut(),
640            HandleObject::null(),
641            space.handle(),
642            Some(stringified),
643            &mut repr as *mut String as *mut _,
644        )
645    };
646    if !stringify_result {
647        return Some("<error converting DOM object to string>".into());
648    }
649    Some(repr.into())
650}
651
652/// Apply sprintf-style substitutions to console format arguments per the WHATWG Console spec.
653///
654/// If the first argument is a string, it is treated as a format string where `%s`, `%d`, `%i`,
655/// `%f`, `%o`, `%O`, and `%c` are replaced by subsequent arguments. Returns the formatted string
656/// and the index of the first argument that was not consumed by a substitution.
657///
658/// <https://console.spec.whatwg.org/#formatter>
659#[expect(unsafe_code)]
660fn apply_sprintf_substitutions(cx: &mut JSContext, messages: &[HandleValue]) -> (String, usize) {
661    debug_assert!(!messages.is_empty() && messages[0].is_string());
662
663    let js_string = ptr::NonNull::new(messages[0].to_string()).unwrap();
664    let format_string = unsafe { jsstr_to_string(cx, js_string) };
665
666    let mut result = String::new();
667    let mut arg_index = 1usize;
668    let mut chars = format_string.chars().peekable();
669
670    while let Some(c) = chars.next() {
671        if c != '%' {
672            result.push(c);
673            continue;
674        }
675
676        match chars.peek().copied() {
677            Some('s') => {
678                chars.next();
679                if arg_index < messages.len() {
680                    result.push_str(&stringify_handle_value(cx, messages[arg_index]).str());
681                    arg_index += 1;
682                } else {
683                    result.push_str("%s");
684                }
685            },
686            Some('d') | Some('i') => {
687                let spec = chars.next().unwrap();
688                if arg_index < messages.len() {
689                    let num = unsafe { ToNumber(cx.raw_cx(), messages[arg_index]) };
690                    if num.is_err() {
691                        unsafe { JS_ClearPendingException(cx) };
692                    }
693                    arg_index += 1;
694                    format_integer_substitution(&mut result, num);
695                } else {
696                    result.push('%');
697                    result.push(spec);
698                }
699            },
700            Some('f') => {
701                chars.next();
702                if arg_index < messages.len() {
703                    let num = unsafe { ToNumber(cx.raw_cx(), messages[arg_index]) };
704                    if num.is_err() {
705                        unsafe { JS_ClearPendingException(cx) };
706                    }
707                    arg_index += 1;
708                    format_float_substitution(&mut result, num);
709                } else {
710                    result.push_str("%f");
711                }
712            },
713            Some('o') | Some('O') => {
714                let spec = chars.next().unwrap();
715                if arg_index < messages.len() {
716                    result.push_str(&stringify_handle_value(cx, messages[arg_index]).str());
717                    arg_index += 1;
718                } else {
719                    result.push('%');
720                    result.push(spec);
721                }
722            },
723            Some('c') => {
724                chars.next();
725                if arg_index < messages.len() {
726                    arg_index += 1; // consume but ignore CSS styling
727                }
728            },
729            Some('%') => {
730                chars.next();
731                result.push('%');
732            },
733            _ => {
734                result.push('%');
735            },
736        }
737    }
738
739    (result, arg_index)
740}
741
742fn format_integer_substitution(result: &mut String, num: Result<f64, ()>) {
743    match num {
744        Ok(n) if n.is_nan() => result.push_str("NaN"),
745        Ok(n) if n == f64::INFINITY => result.push_str("Infinity"),
746        Ok(n) if n == f64::NEG_INFINITY => result.push_str("-Infinity"),
747        Ok(n) => result.push_str(&(n.trunc() as i64).to_string()),
748        Err(_) => result.push_str("NaN"),
749    }
750}
751
752fn format_float_substitution(result: &mut String, num: Result<f64, ()>) {
753    match num {
754        Ok(n) if n.is_nan() => result.push_str("NaN"),
755        Ok(n) if n == f64::INFINITY => result.push_str("Infinity"),
756        Ok(n) if n == f64::NEG_INFINITY => result.push_str("-Infinity"),
757        Ok(n) => result.push_str(&n.to_string()),
758        Err(_) => result.push_str("NaN"),
759    }
760}
761
762fn stringify_handle_values(cx: &mut JSContext, messages: &[HandleValue]) -> DOMString {
763    DOMString::from(itertools::join(
764        messages
765            .iter()
766            .copied()
767            .map(|msg| stringify_handle_value(cx, msg)),
768        " ",
769    ))
770}
771
772/// An implementation of <https://console.spec.whatwg.org/#printer>.
773/// This produces a string version of the argument that is printed to the console.
774fn stringify_debugger_value(value: &DebuggerValue) -> String {
775    match value {
776        DebuggerValue::VoidValue => "undefined".into(),
777        DebuggerValue::NullValue(_) => "null".into(),
778        DebuggerValue::BooleanValue(value) => value.to_string(),
779        DebuggerValue::NumberValue(value) => value.to_string(),
780        DebuggerValue::StringValue(value) => value.clone(),
781        DebuggerValue::ObjectValue { class, preview, .. } => {
782            let Some(preview) = preview else {
783                return class.clone();
784            };
785
786            if preview.kind == "ArrayLike" {
787                let mut items = preview
788                    .items
789                    .as_ref()
790                    .map(|items| {
791                        items
792                            .iter()
793                            .take(MAX_LOG_CHILDREN)
794                            .map(stringify_debugger_value)
795                            .collect::<Vec<_>>()
796                    })
797                    .unwrap_or_default();
798                if preview
799                    .array_length
800                    .is_some_and(|length| length as usize > items.len())
801                {
802                    items.push("...".into());
803                }
804                return format!("[{}]", itertools::join(items, ", "));
805            }
806
807            let mut properties = preview
808                .own_properties
809                .as_ref()
810                .map(|properties| {
811                    properties
812                        .iter()
813                        .take(MAX_LOG_CHILDREN)
814                        .map(|property| {
815                            format!(
816                                "{}: {}",
817                                property.name,
818                                stringify_debugger_value(&property.value)
819                            )
820                        })
821                        .collect::<Vec<_>>()
822                })
823                .unwrap_or_default();
824            if preview
825                .own_properties_length
826                .is_some_and(|length| length as usize > properties.len())
827            {
828                properties.push("...".into());
829            }
830            format!("{class} {{{}}}", itertools::join(properties, ", "))
831        },
832    }
833}
834
835#[derive(Debug, Eq, PartialEq)]
836enum IncludeStackTrace {
837    Yes,
838    No,
839}
840
841impl consoleMethods<crate::DomTypeHolder> for Console {
842    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/log>
843    fn Log(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
844        Console::method(
845            cx,
846            global,
847            ConsoleLogLevel::Log,
848            messages,
849            IncludeStackTrace::No,
850        );
851    }
852
853    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/clear>
854    fn Clear(global: &GlobalScope) {
855        if let Some(chan) = global.devtools_chan() {
856            let worker_id = global
857                .downcast::<WorkerGlobalScope>()
858                .map(|worker| worker.worker_id());
859            let devtools_message =
860                ScriptToDevtoolsControlMsg::ClearConsole(global.pipeline_id(), worker_id);
861            if let Err(error) = chan.send(devtools_message) {
862                log::warn!("Error sending clear message to devtools: {error:?}");
863            }
864        }
865    }
866
867    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console>
868    fn Debug(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
869        Console::method(
870            cx,
871            global,
872            ConsoleLogLevel::Debug,
873            messages,
874            IncludeStackTrace::No,
875        );
876    }
877
878    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/info>
879    fn Info(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
880        Console::method(
881            cx,
882            global,
883            ConsoleLogLevel::Info,
884            messages,
885            IncludeStackTrace::No,
886        );
887    }
888
889    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/warn>
890    fn Warn(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
891        Console::method(
892            cx,
893            global,
894            ConsoleLogLevel::Warn,
895            messages,
896            IncludeStackTrace::No,
897        );
898    }
899
900    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/error>
901    fn Error(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
902        Console::method(
903            cx,
904            global,
905            ConsoleLogLevel::Error,
906            messages,
907            IncludeStackTrace::No,
908        );
909    }
910
911    /// <https://console.spec.whatwg.org/#trace>
912    fn Trace(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
913        Console::method(
914            cx,
915            global,
916            ConsoleLogLevel::Trace,
917            messages,
918            IncludeStackTrace::Yes,
919        );
920    }
921
922    /// <https://console.spec.whatwg.org/#dir>
923    fn Dir(
924        cx: &mut js::context::JSContext,
925        global: &GlobalScope,
926        item: HandleValue,
927        _options: Option<*mut jsapi::JSObject>,
928    ) {
929        // Step 1. Let object be item with generic JavaScript object formatting applied.
930        let argument = console_argument_from_handle_value(cx, item, &mut Vec::new());
931        let prefix = global.current_group_label().unwrap_or_default();
932        // Step 2. Perform Printer("dir", « object », options).
933        Console::send_to_devtools(
934            global,
935            Self::build_message(cx, ConsoleLogLevel::Dir, vec![argument.clone()], None),
936        );
937        Self::send_to_embedder(
938            global,
939            ConsoleLogLevel::Dir,
940            format!("{prefix}{}", stringify_debugger_value(&argument)),
941        );
942    }
943
944    /// <https://developer.mozilla.org/en-US/docs/Web/API/Console/assert>
945    fn Assert(
946        cx: &mut JSContext,
947        global: &GlobalScope,
948        condition: bool,
949        messages: Vec<HandleValue>,
950    ) {
951        if !condition {
952            let message = format!(
953                "Assertion failed: {}",
954                stringify_handle_values(cx, &messages)
955            );
956
957            Console::send_string_message(cx, global, ConsoleLogLevel::Log, message);
958        }
959    }
960
961    /// <https://console.spec.whatwg.org/#time>
962    fn Time(cx: &mut JSContext, global: &GlobalScope, label: DOMString) {
963        if let Ok(()) = global.time(label.clone()) {
964            let message = format!("{label}: timer started");
965            Console::send_string_message(cx, global, ConsoleLogLevel::Log, message);
966        }
967    }
968
969    /// <https://console.spec.whatwg.org/#timelog>
970    fn TimeLog(cx: &mut JSContext, global: &GlobalScope, label: DOMString, data: Vec<HandleValue>) {
971        if let Ok(delta) = global.time_log(&label) {
972            let message = format!("{label}: {delta}ms {}", stringify_handle_values(cx, &data));
973
974            Console::send_string_message(cx, global, ConsoleLogLevel::Log, message);
975        }
976    }
977
978    /// <https://console.spec.whatwg.org/#timeend>
979    fn TimeEnd(cx: &mut JSContext, global: &GlobalScope, label: DOMString) {
980        if let Ok(delta) = global.time_end(&label) {
981            let message = format!("{label}: {delta}ms");
982
983            Console::send_string_message(cx, global, ConsoleLogLevel::Log, message);
984        }
985    }
986
987    /// <https://console.spec.whatwg.org/#group>
988    fn Group(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
989        global.push_console_group(stringify_handle_values(cx, &messages));
990    }
991
992    /// <https://console.spec.whatwg.org/#groupcollapsed>
993    fn GroupCollapsed(cx: &mut JSContext, global: &GlobalScope, messages: Vec<HandleValue>) {
994        global.push_console_group(stringify_handle_values(cx, &messages));
995    }
996
997    /// <https://console.spec.whatwg.org/#groupend>
998    fn GroupEnd(global: &GlobalScope) {
999        global.pop_console_group();
1000    }
1001
1002    /// <https://console.spec.whatwg.org/#count>
1003    fn Count(cx: &mut JSContext, global: &GlobalScope, label: DOMString) {
1004        let count = global.increment_console_count(&label);
1005        let message = format!("{label}: {count}");
1006
1007        Console::send_string_message(cx, global, ConsoleLogLevel::Log, message);
1008    }
1009
1010    /// <https://console.spec.whatwg.org/#countreset>
1011    fn CountReset(cx: &mut JSContext, global: &GlobalScope, label: DOMString) {
1012        if global.reset_console_count(&label).is_err() {
1013            Self::internal_warn(cx, global, format!("Counter “{label}” doesn’t exist."))
1014        }
1015    }
1016}
1017
1018#[expect(unsafe_code)]
1019fn get_js_stack(cx: &mut JSContext) -> Vec<StackFrame> {
1020    const MAX_FRAME_COUNT: u32 = 128;
1021
1022    let mut frames = vec![];
1023    rooted!(&in(cx) let mut handle =  ptr::null_mut());
1024    let captured_js_stack =
1025        unsafe { CapturedJSStack::new(cx.raw_cx(), handle, Some(MAX_FRAME_COUNT)) };
1026    let Some(captured_js_stack) = captured_js_stack else {
1027        return frames;
1028    };
1029
1030    captured_js_stack.for_each_stack_frame(|frame| {
1031        rooted!(&in(cx) let mut result: *mut jsapi::JSString = ptr::null_mut());
1032
1033        // Get function name
1034        unsafe {
1035            GetSavedFrameFunctionDisplayName(
1036                cx,
1037                ptr::null_mut(),
1038                frame,
1039                result.handle_mut(),
1040                SavedFrameSelfHosted::Include,
1041            );
1042        }
1043        let function_name = if let Some(nonnull_result) = ptr::NonNull::new(*result) {
1044            unsafe { jsstr_to_string(cx, nonnull_result) }
1045        } else {
1046            "<anonymous>".into()
1047        };
1048
1049        // Get source file name
1050        result.set(ptr::null_mut());
1051        unsafe {
1052            GetSavedFrameSource(
1053                cx,
1054                ptr::null_mut(),
1055                frame,
1056                result.handle_mut(),
1057                SavedFrameSelfHosted::Include,
1058            );
1059        }
1060        let filename = if let Some(nonnull_result) = ptr::NonNull::new(*result) {
1061            unsafe { jsstr_to_string(cx, nonnull_result) }
1062        } else {
1063            "<anonymous>".into()
1064        };
1065
1066        // get line/column number
1067        let mut line_number = 0;
1068        unsafe {
1069            GetSavedFrameLine(
1070                cx,
1071                ptr::null_mut(),
1072                frame,
1073                &mut line_number,
1074                SavedFrameSelfHosted::Include,
1075            );
1076        }
1077
1078        let mut column_number = jsapi::JS::TaggedColumnNumberOneOrigin { value_: 0 };
1079        unsafe {
1080            GetSavedFrameColumn(
1081                cx,
1082                ptr::null_mut(),
1083                frame,
1084                &mut column_number,
1085                SavedFrameSelfHosted::Include,
1086            );
1087        }
1088        let frame = StackFrame {
1089            filename,
1090            function_name,
1091            line_number,
1092            column_number: column_number.value_,
1093        };
1094
1095        frames.push(frame);
1096    });
1097
1098    frames
1099}
script/dom/console.rs

script/dom/
console.rs
