gecko-dev/devtools/shared/webconsole/js-property-provider.js

1161 строка
34 KiB
JavaScript

/* 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 DevToolsUtils = require("devtools/shared/DevToolsUtils");
const {
evalWithDebugger,
} = require("devtools/server/actors/webconsole/eval-with-debugger");
if (!isWorker) {
loader.lazyRequireGetter(
this,
"getSyntaxTrees",
"devtools/shared/webconsole/parser-helper",
true
);
}
loader.lazyRequireGetter(
this,
"Reflect",
"resource://gre/modules/reflect.jsm",
true
);
// Provide an easy way to bail out of even attempting an autocompletion
// if an object has way too many properties. Protects against large objects
// with numeric values that wouldn't be tallied towards MAX_AUTOCOMPLETIONS.
const MAX_AUTOCOMPLETE_ATTEMPTS = (exports.MAX_AUTOCOMPLETE_ATTEMPTS = 100000);
// Prevent iterating over too many properties during autocomplete suggestions.
const MAX_AUTOCOMPLETIONS = (exports.MAX_AUTOCOMPLETIONS = 1500);
/**
* Provides a list of properties, that are possible matches based on the passed
* Debugger.Environment/Debugger.Object and inputValue.
*
* @param {Object} An object of the following shape:
* - {Object} dbgObject
* When the debugger is not paused this Debugger.Object wraps
* the scope for autocompletion.
* It is null if the debugger is paused.
* - {Object} environment
* When the debugger is paused this Debugger.Environment is the
* scope for autocompletion.
* It is null if the debugger is not paused.
* - {String} inputValue
* Value that should be completed.
* - {Number} cursor (defaults to inputValue.length).
* Optional offset in the input where the cursor is located. If this is
* omitted then the cursor is assumed to be at the end of the input
* value.
* - {Array} authorizedEvaluations (defaults to []).
* Optional array containing all the different properties access that the engine
* can execute in order to retrieve its result's properties.
* ⚠️ This should be set to true *ONLY* on user action as it may cause side-effects
* in the content page ⚠️
* - {WebconsoleActor} webconsoleActor
* A reference to a webconsole actor which we can use to retrieve the last
* evaluation result or create a debuggee value.
* - {String}: selectedNodeActor
* The actor id of the selected node in the inspector.
* - {Array<string>}: expressionVars
* Optional array containing variable defined in the expression. Those variables
* are extracted from CodeMirror state.
* @returns null or object
* If the inputValue is an unsafe getter and invokeUnsafeGetter is false, the
* following form is returned:
*
* {
* isUnsafeGetter: true,
* getterPath: {Array<String>} An array of the property chain leading to the
* getter. Example: ["x", "myGetter"]
* }
*
* If no completion valued could be computed, and the input is not an unsafe
* getter, null is returned.
*
* Otherwise an object with the following form is returned:
* {
* matches: Set<string>
* matchProp: Last part of the inputValue that was used to find
* the matches-strings.
* isElementAccess: Boolean set to true if the evaluation is an element
* access (e.g. `window["addEvent`).
* }
*/
// eslint-disable-next-line complexity
function JSPropertyProvider({
dbgObject,
environment,
inputValue,
cursor,
authorizedEvaluations = [],
webconsoleActor,
selectedNodeActor,
expressionVars = [],
}) {
if (cursor === undefined) {
cursor = inputValue.length;
}
inputValue = inputValue.substring(0, cursor);
// Analyse the inputValue and find the beginning of the last part that
// should be completed.
const inputAnalysis = analyzeInputString(inputValue);
if (!shouldInputBeAutocompleted(inputAnalysis)) {
return null;
}
let {
lastStatement,
isElementAccess,
mainExpression,
matchProp,
isPropertyAccess,
} = inputAnalysis;
// Eagerly evaluate the main expression and return the results properties.
// e.g. `obj.func().a` will evaluate `obj.func()` and return properties matching `a`.
// NOTE: this is only useful when the input has a property access.
if (webconsoleActor && shouldInputBeEagerlyEvaluated(inputAnalysis)) {
const eagerResponse = evalWithDebugger(
mainExpression,
{ eager: true, selectedNodeActor },
webconsoleActor
);
const ret = eagerResponse?.result?.return;
// Only send matches if eager evaluation returned something meaningful
if (ret && ret !== undefined) {
const matches =
typeof ret != "object"
? getMatchedProps(ret, matchProp)
: getMatchedPropsInDbgObject(ret, matchProp);
return prepareReturnedObject({
matches,
search: matchProp,
isElementAccess,
});
}
}
// AST representation of the expression before the last access char (`.` or `[`).
let astExpression;
const startQuoteRegex = /^('|"|`)/;
const env = environment || dbgObject.asEnvironment();
// Catch literals like [1,2,3] or "foo" and return the matches from
// their prototypes.
// Don't run this is a worker, migrating to acorn should allow this
// to run in a worker - Bug 1217198.
if (!isWorker && isPropertyAccess) {
const syntaxTrees = getSyntaxTrees(mainExpression);
const lastTree = syntaxTrees[syntaxTrees.length - 1];
const lastBody = lastTree?.body[lastTree.body.length - 1];
// Finding the last expression since we've sliced up until the dot.
// If there were parse errors this won't exist.
if (lastBody) {
if (!lastBody.expression) {
return null;
}
astExpression = lastBody.expression;
let matchingObject;
if (astExpression.type === "ArrayExpression") {
matchingObject = getContentPrototypeObject(env, "Array");
} else if (
astExpression.type === "Literal" &&
typeof astExpression.value === "string"
) {
matchingObject = getContentPrototypeObject(env, "String");
} else if (
astExpression.type === "Literal" &&
Number.isFinite(astExpression.value)
) {
// The parser rightfuly indicates that we have a number in some cases (e.g. `1.`),
// but we don't want to return Number proto properties in that case since
// the result would be invalid (i.e. `1.toFixed()` throws).
// So if the expression value is an integer, it should not end with `{Number}.`
// (but the following are fine: `1..`, `(1.).`).
if (
!Number.isInteger(astExpression.value) ||
/\d[^\.]{0}\.$/.test(lastStatement) === false
) {
matchingObject = getContentPrototypeObject(env, "Number");
} else {
return null;
}
}
if (matchingObject) {
let search = matchProp;
let elementAccessQuote;
if (isElementAccess && startQuoteRegex.test(matchProp)) {
elementAccessQuote = matchProp[0];
search = matchProp.replace(startQuoteRegex, "");
}
let props = getMatchedPropsInDbgObject(matchingObject, search);
if (isElementAccess) {
props = wrapMatchesInQuotes(props, elementAccessQuote);
}
return {
isElementAccess,
matchProp,
matches: props,
};
}
}
}
// We are completing a variable / a property lookup.
let properties = [];
if (astExpression) {
if (isPropertyAccess) {
properties = getPropertiesFromAstExpression(astExpression);
if (properties === null) {
return null;
}
}
} else {
properties = lastStatement.split(".");
if (isElementAccess) {
const lastPart = properties[properties.length - 1];
const openBracketIndex = lastPart.lastIndexOf("[");
matchProp = lastPart.substr(openBracketIndex + 1);
properties[properties.length - 1] = lastPart.substring(
0,
openBracketIndex
);
} else {
matchProp = properties.pop().trimLeft();
}
}
let search = matchProp;
let elementAccessQuote;
if (isElementAccess && startQuoteRegex.test(search)) {
elementAccessQuote = search[0];
search = search.replace(startQuoteRegex, "");
}
let obj = dbgObject;
if (properties.length === 0) {
const environmentProperties = getMatchedPropsInEnvironment(env, search);
const expressionVariables = new Set(
expressionVars.filter(variableName => variableName.startsWith(matchProp))
);
for (const prop of environmentProperties) {
expressionVariables.add(prop);
}
return {
isElementAccess,
matchProp,
matches: expressionVariables,
};
}
const firstProp = properties.shift().trim();
if (firstProp === "this") {
// Special case for 'this' - try to get the Object from the Environment.
// No problem if it throws, we will just not autocomplete.
try {
obj = env.object;
} catch (e) {
// Ignore.
}
} else if (firstProp === "$_" && webconsoleActor) {
obj = webconsoleActor.getLastConsoleInputEvaluation();
} else if (firstProp === "$0" && selectedNodeActor && webconsoleActor) {
const actor = webconsoleActor.conn.getActor(selectedNodeActor);
if (actor) {
try {
obj = webconsoleActor.makeDebuggeeValue(actor.rawNode);
} catch (e) {
// Ignore.
}
}
} else if (hasArrayIndex(firstProp)) {
obj = getArrayMemberProperty(null, env, firstProp);
} else {
obj = getVariableInEnvironment(env, firstProp);
}
if (!isObjectUsable(obj)) {
return null;
}
// We get the rest of the properties recursively starting from the
// Debugger.Object that wraps the first property
for (let [index, prop] of properties.entries()) {
if (typeof prop === "string") {
prop = prop.trim();
}
if (prop === undefined || prop === null || prop === "") {
return null;
}
const propPath = [firstProp].concat(properties.slice(0, index + 1));
const authorized = authorizedEvaluations.some(
x => JSON.stringify(x) === JSON.stringify(propPath)
);
if (!authorized && DevToolsUtils.isUnsafeGetter(obj, prop)) {
// If we try to access an unsafe getter, return its name so we can consume that
// on the frontend.
return {
isUnsafeGetter: true,
getterPath: propPath,
};
}
if (hasArrayIndex(prop)) {
// The property to autocomplete is a member of array. For example
// list[i][j]..[n]. Traverse the array to get the actual element.
obj = getArrayMemberProperty(obj, null, prop);
} else {
obj = DevToolsUtils.getProperty(obj, prop, authorized);
}
if (!isObjectUsable(obj)) {
return null;
}
}
const matches =
typeof obj != "object"
? getMatchedProps(obj, search)
: getMatchedPropsInDbgObject(obj, search);
return prepareReturnedObject({
matches,
search,
isElementAccess,
elementAccessQuote,
});
}
function shouldInputBeEagerlyEvaluated({ lastStatement }) {
const inComputedProperty =
lastStatement.lastIndexOf("[") !== -1 &&
lastStatement.lastIndexOf("[") > lastStatement.lastIndexOf("]");
const hasPropertyAccess =
lastStatement.includes(".") || lastStatement.includes("[");
return hasPropertyAccess && !inComputedProperty;
}
function shouldInputBeAutocompleted(inputAnalysisState) {
const { err, state, lastStatement } = inputAnalysisState;
// There was an error analysing the string.
if (err) {
console.error("Failed to analyze input string", err);
return false;
}
// If the current state is not STATE_NORMAL, then we are inside of an string
// which means that no completion is possible.
if (state != STATE_NORMAL) {
return false;
}
// Don't complete on just an empty string.
if (lastStatement.trim() == "") {
return false;
}
if (
NO_AUTOCOMPLETE_PREFIXES.some(prefix =>
lastStatement.startsWith(prefix + " ")
)
) {
return false;
}
return true;
}
function hasArrayIndex(str) {
return /\[\d+\]$/.test(str);
}
const STATE_NORMAL = Symbol("STATE_NORMAL");
const STATE_QUOTE = Symbol("STATE_QUOTE");
const STATE_DQUOTE = Symbol("STATE_DQUOTE");
const STATE_TEMPLATE_LITERAL = Symbol("STATE_TEMPLATE_LITERAL");
const STATE_ESCAPE = Symbol("STATE_ESCAPE");
const STATE_SLASH = Symbol("STATE_SLASH");
const STATE_INLINE_COMMENT = Symbol("STATE_INLINE_COMMENT");
const STATE_MULTILINE_COMMENT = Symbol("STATE_MULTILINE_COMMENT");
const STATE_MULTILINE_COMMENT_CLOSE = Symbol("STATE_MULTILINE_COMMENT_CLOSE");
const STATE_QUESTION_MARK = Symbol("STATE_QUESTION_MARK");
const OPEN_BODY = "{[(".split("");
const CLOSE_BODY = "}])".split("");
const OPEN_CLOSE_BODY = {
"{": "}",
"[": "]",
"(": ")",
};
const NO_AUTOCOMPLETE_PREFIXES = ["var", "const", "let", "function", "class"];
const OPERATOR_CHARS_SET = new Set(";,:=<>+-*%|&^~!".split(""));
/**
* Analyses a given string to find the last statement that is interesting for
* later completion.
*
* @param string str
* A string to analyse.
*
* @returns object
* If there was an error in the string detected, then a object like
*
* { err: "ErrorMesssage" }
*
* is returned, otherwise a object like
*
* {
* state: STATE_NORMAL|STATE_QUOTE|STATE_DQUOTE,
* lastStatement: the last statement in the string,
* isElementAccess: boolean that indicates if the lastStatement has an open
* element access (e.g. `x["match`).
* isPropertyAccess: boolean indicating if we are accessing property
* (e.g `true` in `var a = {b: 1};a.b`)
* matchProp: The part of the expression that should match the properties
* on the mainExpression (e.g. `que` when expression is `document.body.que`)
* mainExpression: The part of the expression before any property access,
* (e.g. `a.b` if expression is `a.b.`)
* expressionBeforePropertyAccess: The part of the expression before property access
* (e.g `var a = {b: 1};a` if expression is `var a = {b: 1};a.b`)
* }
*/
// eslint-disable-next-line complexity
function analyzeInputString(str) {
// work variables.
const bodyStack = [];
let state = STATE_NORMAL;
let previousNonWhitespaceChar;
let lastStatement = "";
let currentIndex = -1;
let dotIndex;
let pendingWhitespaceChars = "";
const TIMEOUT = 2500;
const startingTime = Date.now();
// Use a string iterator in order to handle character with a length >= 2 (e.g. 😎).
for (const c of str) {
// We are possibly dealing with a very large string that would take a long time to
// analyze (and freeze the process). If the function has been running for more than
// a given time, we stop the analysis (this isn't too bad because the only
// consequence is that we won't provide autocompletion items).
if (Date.now() - startingTime > TIMEOUT) {
return {
err: "timeout",
};
}
currentIndex += 1;
let resetLastStatement = false;
const isWhitespaceChar = c.trim() === "";
switch (state) {
// Normal JS state.
case STATE_NORMAL:
if (lastStatement.endsWith("?.") && /\d/.test(c)) {
// If the current char is a number, the engine will consider we're not
// performing an optional chaining, but a ternary (e.g. x ?.4 : 2).
lastStatement = "";
}
// Storing the index of dot of the input string
if (c === ".") {
dotIndex = currentIndex;
}
// If the last characters were spaces, and the current one is not.
if (pendingWhitespaceChars && !isWhitespaceChar) {
// If we have a legitimate property/element access, or potential optional
// chaining call, we append the spaces.
if (c === "[" || c === "." || c === "?") {
lastStatement = lastStatement + pendingWhitespaceChars;
} else {
// if not, we can be sure the statement was over, and we can start a new one.
lastStatement = "";
}
pendingWhitespaceChars = "";
}
if (c == '"') {
state = STATE_DQUOTE;
} else if (c == "'") {
state = STATE_QUOTE;
} else if (c == "`") {
state = STATE_TEMPLATE_LITERAL;
} else if (c == "/") {
state = STATE_SLASH;
} else if (c == "?") {
state = STATE_QUESTION_MARK;
} else if (OPERATOR_CHARS_SET.has(c)) {
// If the character is an operator, we can update the current statement.
resetLastStatement = true;
} else if (isWhitespaceChar) {
// If the previous char isn't a dot or opening bracket, and the current computed
// statement is not a variable/function/class declaration, we track the number
// of consecutive spaces, so we can re-use them at some point (or drop them).
if (
previousNonWhitespaceChar !== "." &&
previousNonWhitespaceChar !== "[" &&
!NO_AUTOCOMPLETE_PREFIXES.includes(lastStatement)
) {
pendingWhitespaceChars += c;
continue;
}
} else if (OPEN_BODY.includes(c)) {
// When opening a bracket or a parens, we store the current statement, in order
// to be able to retrieve it later.
bodyStack.push({
token: c,
lastStatement,
index: currentIndex,
});
// And we compute a new statement.
resetLastStatement = true;
} else if (CLOSE_BODY.includes(c)) {
const last = bodyStack.pop();
if (!last || OPEN_CLOSE_BODY[last.token] != c) {
return {
err: "syntax error",
};
}
if (c == "}") {
resetLastStatement = true;
} else {
lastStatement = last.lastStatement;
}
}
break;
// Escaped quote
case STATE_ESCAPE:
state = STATE_NORMAL;
break;
// Double quote state > " <
case STATE_DQUOTE:
if (c == "\\") {
state = STATE_ESCAPE;
} else if (c == "\n") {
return {
err: "unterminated string literal",
};
} else if (c == '"') {
state = STATE_NORMAL;
}
break;
// Template literal state > ` <
case STATE_TEMPLATE_LITERAL:
if (c == "\\") {
state = STATE_ESCAPE;
} else if (c == "`") {
state = STATE_NORMAL;
}
break;
// Single quote state > ' <
case STATE_QUOTE:
if (c == "\\") {
state = STATE_ESCAPE;
} else if (c == "\n") {
return {
err: "unterminated string literal",
};
} else if (c == "'") {
state = STATE_NORMAL;
}
break;
case STATE_SLASH:
if (c == "/") {
state = STATE_INLINE_COMMENT;
} else if (c == "*") {
state = STATE_MULTILINE_COMMENT;
} else {
lastStatement = "";
state = STATE_NORMAL;
}
break;
case STATE_INLINE_COMMENT:
if (c === "\n") {
state = STATE_NORMAL;
resetLastStatement = true;
}
break;
case STATE_MULTILINE_COMMENT:
if (c === "*") {
state = STATE_MULTILINE_COMMENT_CLOSE;
}
break;
case STATE_MULTILINE_COMMENT_CLOSE:
if (c === "/") {
state = STATE_NORMAL;
resetLastStatement = true;
} else {
state = STATE_MULTILINE_COMMENT;
}
break;
case STATE_QUESTION_MARK:
state = STATE_NORMAL;
if (c === "?") {
// If we have a nullish coalescing operator, we start a new statement
resetLastStatement = true;
} else if (c !== ".") {
// If we're not dealing with optional chaining (?.), it means we have a ternary,
// so we are starting a new statement that includes the current character.
lastStatement = "";
} else {
dotIndex = currentIndex;
}
break;
}
if (!isWhitespaceChar) {
previousNonWhitespaceChar = c;
}
if (resetLastStatement) {
lastStatement = "";
} else {
lastStatement = lastStatement + c;
}
// We update all the open stacks lastStatement so they are up-to-date.
bodyStack.forEach(stack => {
if (stack.token !== "}") {
stack.lastStatement = stack.lastStatement + c;
}
});
}
let isElementAccess = false;
let lastOpeningBracketIndex = -1;
if (bodyStack.length === 1 && bodyStack[0].token === "[") {
lastStatement = bodyStack[0].lastStatement;
lastOpeningBracketIndex = bodyStack[0].index;
isElementAccess = true;
if (
state === STATE_DQUOTE ||
state === STATE_QUOTE ||
state === STATE_TEMPLATE_LITERAL ||
state === STATE_ESCAPE
) {
state = STATE_NORMAL;
}
} else if (pendingWhitespaceChars) {
lastStatement = "";
}
const lastCompletionCharIndex = isElementAccess
? lastOpeningBracketIndex
: dotIndex;
const stringBeforeLastCompletionChar = str.slice(0, lastCompletionCharIndex);
const isPropertyAccess =
lastCompletionCharIndex && lastCompletionCharIndex > 0;
// Compute `isOptionalAccess`, so that we can use it
// later for computing `expressionBeforePropertyAccess`.
//Check `?.` before `[` for element access ( e.g `a?.["b` or `a ?. ["b` )
// and `?` before `.` for regular property access ( e.g `a?.b` or `a ?. b` )
const optionalElementAccessRegex = /\?\.\s*$/;
const isOptionalAccess = isElementAccess
? optionalElementAccessRegex.test(stringBeforeLastCompletionChar)
: isPropertyAccess &&
str.slice(lastCompletionCharIndex - 1, lastCompletionCharIndex + 1) ===
"?.";
// Get the filtered string for the properties (e.g if `document.qu` then `qu`)
const matchProp = isPropertyAccess
? str.slice(lastCompletionCharIndex + 1).trimLeft()
: null;
const expressionBeforePropertyAccess = isPropertyAccess
? str.slice(
0,
// For optional access, we can take all the chars before the last "?" char.
isOptionalAccess
? stringBeforeLastCompletionChar.lastIndexOf("?")
: lastCompletionCharIndex
)
: str;
let mainExpression = lastStatement;
if (isPropertyAccess) {
if (isOptionalAccess) {
// Strip anything before the last `?`.
mainExpression = mainExpression.slice(0, mainExpression.lastIndexOf("?"));
} else {
mainExpression = mainExpression.slice(
0,
-1 * (str.length - lastCompletionCharIndex)
);
}
}
mainExpression = mainExpression.trim();
return {
state,
isElementAccess,
isPropertyAccess,
expressionBeforePropertyAccess,
lastStatement,
mainExpression,
matchProp,
};
}
/**
* For a given environment and constructor name, returns its Debugger.Object wrapped
* prototype.
*
* @param {Environment} env
* @param {String} name: Name of the constructor object we want the prototype of.
* @returns {Debugger.Object|null} the prototype, or null if it not found.
*/
function getContentPrototypeObject(env, name) {
// Retrieve the outermost environment to get the global object.
let outermostEnv = env;
while (outermostEnv?.parent) {
outermostEnv = outermostEnv.parent;
}
const constructorObj = DevToolsUtils.getProperty(outermostEnv.object, name);
if (!constructorObj) {
return null;
}
return DevToolsUtils.getProperty(constructorObj, "prototype");
}
/**
* @param {Object} ast: An AST representing a property access (e.g. `foo.bar["baz"].x`)
* @returns {Array|null} An array representing the property access
* (e.g. ["foo", "bar", "baz", "x"]).
*/
function getPropertiesFromAstExpression(ast) {
let result = [];
if (!ast) {
return result;
}
const { type, property, object, name, expression } = ast;
if (type === "ThisExpression") {
result.unshift("this");
} else if (type === "Identifier" && name) {
result.unshift(name);
} else if (type === "OptionalExpression" && expression) {
result = (getPropertiesFromAstExpression(expression) || []).concat(result);
} else if (
type === "MemberExpression" ||
type === "OptionalMemberExpression"
) {
if (property) {
if (property.type === "Identifier" && property.name) {
result.unshift(property.name);
} else if (property.type === "Literal") {
result.unshift(property.value);
}
}
if (object) {
result = (getPropertiesFromAstExpression(object) || []).concat(result);
}
} else {
return null;
}
return result;
}
function wrapMatchesInQuotes(matches, quote = `"`) {
return new Set(
[...matches].map(p => {
// Escape as a double-quoted string literal
p = JSON.stringify(p);
// We don't have to do anything more when using double quotes
if (quote == `"`) {
return p;
}
// Remove surrounding double quotes
p = p.slice(1, -1);
// Unescape inner double quotes (all must be escaped, so no need to count backslashes)
p = p.replace(/\\(?=")/g, "");
// Escape the specified quote (assuming ' or `, which are treated literally in regex)
p = p.replace(new RegExp(quote, "g"), "\\$&");
// Template literals treat ${ specially, escape it
if (quote == "`") {
p = p.replace(/\${/g, "\\$&");
}
// Surround the result with quotes
return `${quote}${p}${quote}`;
})
);
}
/**
* Get the array member of obj for the given prop. For example, given
* prop='list[0][1]' the element at [0][1] of obj.list is returned.
*
* @param object obj
* The object to operate on. Should be null if env is passed.
* @param object env
* The Environment to operate in. Should be null if obj is passed.
* @param string prop
* The property to return.
* @return null or Object
* Returns null if the property couldn't be located. Otherwise the array
* member identified by prop.
*/
function getArrayMemberProperty(obj, env, prop) {
// First get the array.
const propWithoutIndices = prop.substr(0, prop.indexOf("["));
if (env) {
obj = getVariableInEnvironment(env, propWithoutIndices);
} else {
obj = DevToolsUtils.getProperty(obj, propWithoutIndices);
}
if (!isObjectUsable(obj)) {
return null;
}
// Then traverse the list of indices to get the actual element.
let result;
const arrayIndicesRegex = /\[[^\]]*\]/g;
while ((result = arrayIndicesRegex.exec(prop)) !== null) {
const indexWithBrackets = result[0];
const indexAsText = indexWithBrackets.substr(
1,
indexWithBrackets.length - 2
);
const index = parseInt(indexAsText, 10);
if (isNaN(index)) {
return null;
}
obj = DevToolsUtils.getProperty(obj, index);
if (!isObjectUsable(obj)) {
return null;
}
}
return obj;
}
/**
* Check if the given Debugger.Object can be used for autocomplete.
*
* @param Debugger.Object object
* The Debugger.Object to check.
* @return boolean
* True if further inspection into the object is possible, or false
* otherwise.
*/
function isObjectUsable(object) {
if (object == null) {
return false;
}
if (typeof object == "object" && object.class == "DeadObject") {
return false;
}
return true;
}
/**
* @see getExactMatchImpl()
*/
function getVariableInEnvironment(environment, name) {
return getExactMatchImpl(environment, name, DebuggerEnvironmentSupport);
}
function prepareReturnedObject({
matches,
search,
isElementAccess,
elementAccessQuote,
}) {
if (isElementAccess) {
// If it's an element access, we need to wrap properties in quotes (either the one
// the user already typed, or `"`).
matches = wrapMatchesInQuotes(matches, elementAccessQuote);
} else if (!isWorker) {
// If we're not performing an element access, we need to check that the property
// are suited for a dot access. (Reflect.jsm is not available in worker context yet,
// see Bug 1507181).
for (const match of matches) {
try {
// In order to know if the property is suited for dot notation, we use Reflect
// to parse an expression where we try to access the property with a dot. If it
// throws, this means that we need to do an element access instead.
Reflect.parse(`({${match}: true})`);
} catch (e) {
matches.delete(match);
}
}
}
return { isElementAccess, matchProp: search, matches };
}
/**
* @see getMatchedPropsImpl()
*/
function getMatchedPropsInEnvironment(environment, match) {
return getMatchedPropsImpl(environment, match, DebuggerEnvironmentSupport);
}
/**
* @see getMatchedPropsImpl()
*/
function getMatchedPropsInDbgObject(dbgObject, match) {
return getMatchedPropsImpl(dbgObject, match, DebuggerObjectSupport);
}
/**
* @see getMatchedPropsImpl()
*/
function getMatchedProps(obj, match) {
if (typeof obj != "object") {
obj = obj.constructor.prototype;
}
return getMatchedPropsImpl(obj, match, JSObjectSupport);
}
/**
* Get all properties in the given object (and its parent prototype chain) that
* match a given prefix.
*
* @param {Mixed} obj
* Object whose properties we want to filter.
* @param {string} match
* Filter for properties that match this string.
* @returns {Set} List of matched properties.
*/
function getMatchedPropsImpl(obj, match, { chainIterator, getProperties }) {
const matches = new Set();
let numProps = 0;
const insensitiveMatching = match && match[0].toUpperCase() !== match[0];
const propertyMatches = prop => {
return insensitiveMatching
? prop.toLocaleLowerCase().startsWith(match.toLocaleLowerCase())
: prop.startsWith(match);
};
// We need to go up the prototype chain.
const iter = chainIterator(obj);
for (obj of iter) {
const props = getProperties(obj);
if (!props) {
continue;
}
numProps += props.length;
// If there are too many properties to event attempt autocompletion,
// or if we have already added the max number, then stop looping
// and return the partial set that has already been discovered.
if (
numProps >= MAX_AUTOCOMPLETE_ATTEMPTS ||
matches.size >= MAX_AUTOCOMPLETIONS
) {
break;
}
for (let i = 0; i < props.length; i++) {
const prop = props[i];
if (!propertyMatches(prop)) {
continue;
}
// If it is an array index, we can't take it.
// This uses a trick: converting a string to a number yields NaN if
// the operation failed, and NaN is not equal to itself.
// eslint-disable-next-line no-self-compare
if (+prop != +prop) {
matches.add(prop);
}
if (matches.size >= MAX_AUTOCOMPLETIONS) {
break;
}
}
}
return matches;
}
/**
* Returns a property value based on its name from the given object, by
* recursively checking the object's prototype.
*
* @param object obj
* An object to look the property into.
* @param string name
* The property that is looked up.
* @returns object|undefined
* A Debugger.Object if the property exists in the object's prototype
* chain, undefined otherwise.
*/
function getExactMatchImpl(obj, name, { chainIterator, getProperty }) {
// We need to go up the prototype chain.
const iter = chainIterator(obj);
for (obj of iter) {
const prop = getProperty(obj, name, obj);
if (prop) {
return prop.value;
}
}
return undefined;
}
var JSObjectSupport = {
chainIterator: function*(obj) {
while (obj) {
yield obj;
try {
obj = Object.getPrototypeOf(obj);
} catch (error) {
// The above can throw e.g. for some proxy objects.
return;
}
}
},
getProperties: function(obj) {
try {
return Object.getOwnPropertyNames(obj);
} catch (error) {
// The above can throw e.g. for some proxy objects.
return null;
}
},
getProperty: function() {
// getProperty is unsafe with raw JS objects.
throw new Error("Unimplemented!");
},
};
var DebuggerObjectSupport = {
chainIterator: function*(obj) {
while (obj) {
yield obj;
try {
obj = obj.proto;
} catch (error) {
// The above can throw e.g. for some proxy objects.
return;
}
}
},
getProperties: function(obj) {
try {
return obj.getOwnPropertyNames();
} catch (error) {
// The above can throw e.g. for some proxy objects.
return null;
}
},
getProperty: function(obj, name, rootObj) {
// This is left unimplemented in favor to DevToolsUtils.getProperty().
throw new Error("Unimplemented!");
},
};
var DebuggerEnvironmentSupport = {
chainIterator: function*(obj) {
while (obj) {
yield obj;
obj = obj.parent;
}
},
getProperties: function(obj) {
const names = obj.names();
// Include 'this' in results (in sorted order)
for (let i = 0; i < names.length; i++) {
if (i === names.length - 1 || names[i + 1] > "this") {
names.splice(i + 1, 0, "this");
break;
}
}
return names;
},
getProperty: function(obj, name) {
let result;
// Try/catch since name can be anything, and getVariable throws if
// it's not a valid ECMAScript identifier name
try {
// TODO: we should use getVariableDescriptor() here - bug 725815.
result = obj.getVariable(name);
} catch (e) {
// Ignore.
}
// FIXME: Need actual UI, bug 941287.
if (
result == null ||
(typeof result == "object" &&
(result.optimizedOut || result.missingArguments))
) {
return null;
}
return { value: result };
},
};
exports.JSPropertyProvider = DevToolsUtils.makeInfallible(JSPropertyProvider);
// Export a version that will throw (for tests)
exports.FallibleJSPropertyProvider = JSPropertyProvider;
// Export analyzeInputString (for tests)
exports.analyzeInputString = analyzeInputString;