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|
'use strict';
const {
MathMin,
Set,
Symbol,
} = primordials;
const { tokTypes: tt, Parser: AcornParser } =
require('internal/deps/acorn/acorn/dist/acorn');
const privateMethods =
require('internal/deps/acorn-plugins/acorn-private-methods/index');
const classFields =
require('internal/deps/acorn-plugins/acorn-class-fields/index');
const numericSeparator =
require('internal/deps/acorn-plugins/acorn-numeric-separator/index');
const staticClassFeatures =
require('internal/deps/acorn-plugins/acorn-static-class-features/index');
const { sendInspectorCommand } = require('internal/util/inspector');
const {
ERR_INSPECTOR_NOT_AVAILABLE
} = require('internal/errors').codes;
const {
clearLine,
clearScreenDown,
cursorTo,
moveCursor,
} = require('readline');
const {
commonPrefix,
kSubstringSearch,
} = require('internal/readline/utils');
const {
getStringWidth,
inspect,
} = require('internal/util/inspect');
let debug = require('internal/util/debuglog').debuglog('repl', (fn) => {
debug = fn;
});
const previewOptions = {
colors: false,
depth: 1,
showHidden: false
};
const REPL_MODE_STRICT = Symbol('repl-strict');
// If the error is that we've unexpectedly ended the input,
// then let the user try to recover by adding more input.
// Note: `e` (the original exception) is not used by the current implementation,
// but may be needed in the future.
function isRecoverableError(e, code) {
// For similar reasons as `defaultEval`, wrap expressions starting with a
// curly brace with parenthesis. Note: only the open parenthesis is added
// here as the point is to test for potentially valid but incomplete
// expressions.
if (/^\s*\{/.test(code) && isRecoverableError(e, `(${code}`)) return true;
let recoverable = false;
// Determine if the point of any error raised is at the end of the input.
// There are two cases to consider:
//
// 1. Any error raised after we have encountered the 'eof' token.
// This prevents us from declaring partial tokens (like '2e') as
// recoverable.
//
// 2. Three cases where tokens can legally span lines. This is
// template, comment, and strings with a backslash at the end of
// the line, indicating a continuation. Note that we need to look
// for the specific errors of 'unterminated' kind (not, for example,
// a syntax error in a ${} expression in a template), and the only
// way to do that currently is to look at the message. Should Acorn
// change these messages in the future, this will lead to a test
// failure, indicating that this code needs to be updated.
//
const RecoverableParser = AcornParser
.extend(
privateMethods,
classFields,
numericSeparator,
staticClassFeatures,
(Parser) => {
return class extends Parser {
nextToken() {
super.nextToken();
if (this.type === tt.eof)
recoverable = true;
}
raise(pos, message) {
switch (message) {
case 'Unterminated template':
case 'Unterminated comment':
recoverable = true;
break;
case 'Unterminated string constant':
const token = this.input.slice(this.lastTokStart, this.pos);
// See https://www.ecma-international.org/ecma-262/#sec-line-terminators
if (/\\(?:\r\n?|\n|\u2028|\u2029)$/.test(token)) {
recoverable = true;
}
}
super.raise(pos, message);
}
};
}
);
// Try to parse the code with acorn. If the parse fails, ignore the acorn
// error and return the recoverable status.
try {
RecoverableParser.parse(code, { ecmaVersion: 11 });
// Odd case: the underlying JS engine (V8, Chakra) rejected this input
// but Acorn detected no issue. Presume that additional text won't
// address this issue.
return false;
} catch {
return recoverable;
}
}
function setupPreview(repl, contextSymbol, bufferSymbol, active) {
// Simple terminals can't handle previews.
if (process.env.TERM === 'dumb' || !active) {
return { showPreview() {}, clearPreview() {} };
}
let inputPreview = null;
let lastInputPreview = '';
let previewCompletionCounter = 0;
let completionPreview = null;
let hasCompletions = false;
let wrapped = false;
let escaped = null;
function getPreviewPos() {
const displayPos = repl._getDisplayPos(`${repl._prompt}${repl.line}`);
const cursorPos = repl.line.length !== repl.cursor ?
repl.getCursorPos() :
displayPos;
return { displayPos, cursorPos };
}
function isCursorAtInputEnd() {
const { cursorPos, displayPos } = getPreviewPos();
return cursorPos.rows === displayPos.rows &&
cursorPos.cols === displayPos.cols;
}
const clearPreview = (key) => {
if (inputPreview !== null) {
const { displayPos, cursorPos } = getPreviewPos();
const rows = displayPos.rows - cursorPos.rows + 1;
moveCursor(repl.output, 0, rows);
clearLine(repl.output);
moveCursor(repl.output, 0, -rows);
lastInputPreview = inputPreview;
inputPreview = null;
}
if (completionPreview !== null) {
// Prevent cursor moves if not necessary!
const move = repl.line.length !== repl.cursor;
let pos, rows;
if (move) {
pos = getPreviewPos();
cursorTo(repl.output, pos.displayPos.cols);
rows = pos.displayPos.rows - pos.cursorPos.rows;
moveCursor(repl.output, 0, rows);
}
const totalLine = `${repl._prompt}${repl.line}${completionPreview}`;
const newPos = repl._getDisplayPos(totalLine);
// Minimize work for the terminal. It is enough to clear the right part of
// the current line in case the preview is visible on a single line.
if (newPos.rows === 0 || (pos && pos.displayPos.rows === newPos.rows)) {
clearLine(repl.output, 1);
} else {
clearScreenDown(repl.output);
}
if (move) {
cursorTo(repl.output, pos.cursorPos.cols);
moveCursor(repl.output, 0, -rows);
}
if (!key.ctrl && !key.shift) {
if (key.name === 'escape') {
if (escaped === null && key.meta) {
escaped = repl.line;
}
} else if ((key.name === 'return' || key.name === 'enter') &&
!key.meta &&
escaped !== repl.line &&
isCursorAtInputEnd()) {
repl._insertString(completionPreview);
}
}
completionPreview = null;
}
if (escaped !== repl.line) {
escaped = null;
}
};
function showCompletionPreview(line, insertPreview) {
previewCompletionCounter++;
const count = previewCompletionCounter;
repl.completer(line, (error, data) => {
// Tab completion might be async and the result might already be outdated.
if (count !== previewCompletionCounter) {
return;
}
if (error) {
debug('Error while generating completion preview', error);
return;
}
// Result and the text that was completed.
const [rawCompletions, completeOn] = data;
if (!rawCompletions || rawCompletions.length === 0) {
return;
}
hasCompletions = true;
// If there is a common prefix to all matches, then apply that portion.
const completions = rawCompletions.filter((e) => e);
const prefix = commonPrefix(completions);
// No common prefix found.
if (prefix.length <= completeOn.length) {
return;
}
const suffix = prefix.slice(completeOn.length);
if (insertPreview) {
repl._insertString(suffix);
return;
}
completionPreview = suffix;
const result = repl.useColors ?
`\u001b[90m${suffix}\u001b[39m` :
` // ${suffix}`;
const { cursorPos, displayPos } = getPreviewPos();
if (repl.line.length !== repl.cursor) {
cursorTo(repl.output, displayPos.cols);
moveCursor(repl.output, 0, displayPos.rows - cursorPos.rows);
}
repl.output.write(result);
cursorTo(repl.output, cursorPos.cols);
const totalLine = `${repl._prompt}${repl.line}${suffix}`;
const newPos = repl._getDisplayPos(totalLine);
const rows = newPos.rows - cursorPos.rows - (newPos.cols === 0 ? 1 : 0);
moveCursor(repl.output, 0, -rows);
});
}
function isInStrictMode(repl) {
return repl.replMode === REPL_MODE_STRICT || process.execArgv
.map((e) => e.toLowerCase().replace(/_/g, '-'))
.includes('--use-strict');
}
// This returns a code preview for arbitrary input code.
function getInputPreview(input, callback) {
// For similar reasons as `defaultEval`, wrap expressions starting with a
// curly brace with parenthesis.
if (input.startsWith('{') && !input.endsWith(';') && !wrapped) {
input = `(${input})`;
wrapped = true;
}
sendInspectorCommand((session) => {
session.post('Runtime.evaluate', {
expression: input,
throwOnSideEffect: true,
timeout: 333,
contextId: repl[contextSymbol],
}, (error, preview) => {
if (error) {
callback(error);
return;
}
const { result } = preview;
if (result.value !== undefined) {
callback(null, inspect(result.value, previewOptions));
// Ignore EvalErrors, SyntaxErrors and ReferenceErrors. It is not clear
// where they came from and if they are recoverable or not. Other errors
// may be inspected.
} else if (preview.exceptionDetails &&
(result.className === 'EvalError' ||
result.className === 'SyntaxError' ||
// Report ReferenceError in case the strict mode is active
// for input that has no completions.
(result.className === 'ReferenceError' &&
(hasCompletions || !isInStrictMode(repl))))) {
callback(null, null);
} else if (result.objectId) {
// The writer options might change and have influence on the inspect
// output. The user might change e.g., `showProxy`, `getters` or
// `showHidden`. Use `inspect` instead of `JSON.stringify` to keep
// `Infinity` and similar intact.
const inspectOptions = inspect({
...repl.writer.options,
colors: false,
depth: 1,
compact: true,
breakLength: Infinity
}, previewOptions);
session.post('Runtime.callFunctionOn', {
functionDeclaration: `(v) => util.inspect(v, ${inspectOptions})`,
objectId: result.objectId,
arguments: [result]
}, (error, preview) => {
if (error) {
callback(error);
} else {
callback(null, preview.result.value);
}
});
} else {
// Either not serializable or undefined.
callback(null, result.unserializableValue || result.type);
}
});
}, () => callback(new ERR_INSPECTOR_NOT_AVAILABLE()));
}
const showPreview = () => {
// Prevent duplicated previews after a refresh.
if (inputPreview !== null || !repl.isCompletionEnabled) {
return;
}
const line = repl.line.trim();
// Do not preview in case the line only contains whitespace.
if (line === '') {
return;
}
hasCompletions = false;
// Add the autocompletion preview.
const insertPreview = false;
showCompletionPreview(repl.line, insertPreview);
// Do not preview if the command is buffered.
if (repl[bufferSymbol]) {
return;
}
const inputPreviewCallback = (error, inspected) => {
if (inspected === null) {
return;
}
wrapped = false;
// Ignore the output if the value is identical to the current line and the
// former preview is not identical to this preview.
if (line === inspected && lastInputPreview !== inspected) {
return;
}
if (error) {
debug('Error while generating preview', error);
return;
}
// Do not preview `undefined` if colors are deactivated or explicitly
// requested.
if (inspected === 'undefined' &&
(!repl.useColors || repl.ignoreUndefined)) {
return;
}
inputPreview = inspected;
// Limit the output to maximum 250 characters. Otherwise it becomes a)
// difficult to read and b) non terminal REPLs would visualize the whole
// output.
let maxColumns = MathMin(repl.columns, 250);
// Support unicode characters of width other than one by checking the
// actual width.
if (inspected.length * 2 >= maxColumns &&
getStringWidth(inspected) > maxColumns) {
maxColumns -= 4 + (repl.useColors ? 0 : 3);
let res = '';
for (const char of inspected) {
maxColumns -= getStringWidth(char);
if (maxColumns < 0)
break;
res += char;
}
inspected = `${res}...`;
}
// Line breaks are very rare and probably only occur in case of error
// messages with line breaks.
const lineBreakPos = inspected.indexOf('\n');
if (lineBreakPos !== -1) {
inspected = `${inspected.slice(0, lineBreakPos)}`;
}
const result = repl.useColors ?
`\u001b[90m${inspected}\u001b[39m` :
`// ${inspected}`;
const { cursorPos, displayPos } = getPreviewPos();
const rows = displayPos.rows - cursorPos.rows;
moveCursor(repl.output, 0, rows);
repl.output.write(`\n${result}`);
cursorTo(repl.output, cursorPos.cols);
moveCursor(repl.output, 0, -rows - 1);
};
let previewLine = line;
if (completionPreview !== null &&
isCursorAtInputEnd() &&
escaped !== repl.line) {
previewLine += completionPreview;
}
getInputPreview(previewLine, inputPreviewCallback);
if (wrapped) {
getInputPreview(previewLine, inputPreviewCallback);
}
wrapped = false;
};
// -------------------------------------------------------------------------//
// Replace multiple interface functions. This is required to fully support //
// previews without changing readlines behavior. //
// -------------------------------------------------------------------------//
// Refresh prints the whole screen again and the preview will be removed
// during that procedure. Print the preview again. This also makes sure
// the preview is always correct after resizing the terminal window.
const originalRefresh = repl._refreshLine.bind(repl);
repl._refreshLine = () => {
inputPreview = null;
originalRefresh();
showPreview();
};
let insertCompletionPreview = true;
// Insert the longest common suffix of the current input in case the user
// moves to the right while already being at the current input end.
const originalMoveCursor = repl._moveCursor.bind(repl);
repl._moveCursor = (dx) => {
const currentCursor = repl.cursor;
originalMoveCursor(dx);
if (currentCursor + dx > repl.line.length &&
typeof repl.completer === 'function' &&
insertCompletionPreview) {
const insertPreview = true;
showCompletionPreview(repl.line, insertPreview);
}
};
// This is the only function that interferes with the completion insertion.
// Monkey patch it to prevent inserting the completion when it shouldn't be.
const originalClearLine = repl.clearLine.bind(repl);
repl.clearLine = () => {
insertCompletionPreview = false;
originalClearLine();
insertCompletionPreview = true;
};
return { showPreview, clearPreview };
}
function setupReverseSearch(repl) {
// Simple terminals can't use reverse search.
if (process.env.TERM === 'dumb') {
return { reverseSearch() { return false; } };
}
const alreadyMatched = new Set();
const labels = {
r: 'bck-i-search: ',
s: 'fwd-i-search: '
};
let isInReverseSearch = false;
let historyIndex = -1;
let input = '';
let cursor = -1;
let dir = 'r';
let lastMatch = -1;
let lastCursor = -1;
let promptPos;
function checkAndSetDirectionKey(keyName) {
if (!labels[keyName]) {
return false;
}
if (dir !== keyName) {
// Reset the already matched set in case the direction is changed. That
// way it's possible to find those entries again.
alreadyMatched.clear();
dir = keyName;
}
return true;
}
function goToNextHistoryIndex() {
// Ignore this entry for further searches and continue to the next
// history entry.
alreadyMatched.add(repl.history[historyIndex]);
historyIndex += dir === 'r' ? 1 : -1;
cursor = -1;
}
function search() {
// Just print an empty line in case the user removed the search parameter.
if (input === '') {
print(repl.line, `${labels[dir]}_`);
return;
}
// Fix the bounds in case the direction has changed in the meanwhile.
if (dir === 'r') {
if (historyIndex < 0) {
historyIndex = 0;
}
} else if (historyIndex >= repl.history.length) {
historyIndex = repl.history.length - 1;
}
// Check the history entries until a match is found.
while (historyIndex >= 0 && historyIndex < repl.history.length) {
let entry = repl.history[historyIndex];
// Visualize all potential matches only once.
if (alreadyMatched.has(entry)) {
historyIndex += dir === 'r' ? 1 : -1;
continue;
}
// Match the next entry either from the start or from the end, depending
// on the current direction.
if (dir === 'r') {
// Update the cursor in case it's necessary.
if (cursor === -1) {
cursor = entry.length;
}
cursor = entry.lastIndexOf(input, cursor - 1);
} else {
cursor = entry.indexOf(input, cursor + 1);
}
// Match not found.
if (cursor === -1) {
goToNextHistoryIndex();
// Match found.
} else {
if (repl.useColors) {
const start = entry.slice(0, cursor);
const end = entry.slice(cursor + input.length);
entry = `${start}\x1B[4m${input}\x1B[24m${end}`;
}
print(entry, `${labels[dir]}${input}_`, cursor);
lastMatch = historyIndex;
lastCursor = cursor;
// Explicitly go to the next history item in case no further matches are
// possible with the current entry.
if ((dir === 'r' && cursor === 0) ||
(dir === 's' && entry.length === cursor + input.length)) {
goToNextHistoryIndex();
}
return;
}
}
print(repl.line, `failed-${labels[dir]}${input}_`);
}
function print(outputLine, inputLine, cursor = repl.cursor) {
// TODO(BridgeAR): Resizing the terminal window hides the overlay. To fix
// that, readline must be aware of this information. It's probably best to
// add a couple of properties to readline that allow to do the following:
// 1. Add arbitrary data to the end of the current line while not counting
// towards the line. This would be useful for the completion previews.
// 2. Add arbitrary extra lines that do not count towards the regular line.
// This would be useful for both, the input preview and the reverse
// search. It might be combined with the first part?
// 3. Add arbitrary input that is "on top" of the current line. That is
// useful for the reverse search.
// 4. To trigger the line refresh, functions should be used to pass through
// the information. Alternatively, getters and setters could be used.
// That might even be more elegant.
// The data would then be accounted for when calling `_refreshLine()`.
// This function would then look similar to:
// repl.overlay(outputLine);
// repl.addTrailingLine(inputLine);
// repl.setCursor(cursor);
// More potential improvements: use something similar to stream.cork().
// Multiple cursor moves on the same tick could be prevented in case all
// writes from the same tick are combined and the cursor is moved at the
// tick end instead of after each operation.
let rows = 0;
if (lastMatch !== -1) {
const line = repl.history[lastMatch].slice(0, lastCursor);
rows = repl._getDisplayPos(`${repl._prompt}${line}`).rows;
cursorTo(repl.output, promptPos.cols);
} else if (isInReverseSearch && repl.line !== '') {
rows = repl.getCursorPos().rows;
cursorTo(repl.output, promptPos.cols);
}
if (rows !== 0)
moveCursor(repl.output, 0, -rows);
if (isInReverseSearch) {
clearScreenDown(repl.output);
repl.output.write(`${outputLine}\n${inputLine}`);
} else {
repl.output.write(`\n${inputLine}`);
}
lastMatch = -1;
// To know exactly how many rows we have to move the cursor back we need the
// cursor rows, the output rows and the input rows.
const prompt = repl._prompt;
const cursorLine = `${prompt}${outputLine.slice(0, cursor)}`;
const cursorPos = repl._getDisplayPos(cursorLine);
const outputPos = repl._getDisplayPos(`${prompt}${outputLine}`);
const inputPos = repl._getDisplayPos(inputLine);
const inputRows = inputPos.rows - (inputPos.cols === 0 ? 1 : 0);
rows = -1 - inputRows - (outputPos.rows - cursorPos.rows);
moveCursor(repl.output, 0, rows);
cursorTo(repl.output, cursorPos.cols);
}
function reset(string) {
isInReverseSearch = string !== undefined;
// In case the reverse search ends and a history entry is found, reset the
// line to the found entry.
if (!isInReverseSearch) {
if (lastMatch !== -1) {
repl.line = repl.history[lastMatch];
repl.cursor = lastCursor;
repl.historyIndex = lastMatch;
}
lastMatch = -1;
// Clear screen and write the current repl.line before exiting.
cursorTo(repl.output, promptPos.cols);
moveCursor(repl.output, 0, promptPos.rows);
clearScreenDown(repl.output);
if (repl.line !== '') {
repl.output.write(repl.line);
if (repl.line.length !== repl.cursor) {
const { cols, rows } = repl.getCursorPos();
cursorTo(repl.output, cols);
moveCursor(repl.output, 0, rows);
}
}
}
input = string || '';
cursor = -1;
historyIndex = repl.historyIndex;
alreadyMatched.clear();
}
function reverseSearch(string, key) {
if (!isInReverseSearch) {
if (key.ctrl && checkAndSetDirectionKey(key.name)) {
historyIndex = repl.historyIndex;
promptPos = repl._getDisplayPos(`${repl._prompt}`);
print(repl.line, `${labels[dir]}_`);
isInReverseSearch = true;
}
} else if (key.ctrl && checkAndSetDirectionKey(key.name)) {
search();
} else if (key.name === 'backspace' ||
(key.ctrl && (key.name === 'h' || key.name === 'w'))) {
reset(input.slice(0, input.length - 1));
search();
// Special handle <ctrl> + c and escape. Those should only cancel the
// reverse search. The original line is visible afterwards again.
} else if ((key.ctrl && key.name === 'c') || key.name === 'escape') {
lastMatch = -1;
reset();
return true;
// End search in case either enter is pressed or if any non-reverse-search
// key (combination) is pressed.
} else if (key.ctrl ||
key.meta ||
key.name === 'return' ||
key.name === 'enter' ||
typeof string !== 'string' ||
string === '') {
reset();
repl[kSubstringSearch] = '';
} else {
reset(`${input}${string}`);
search();
}
return isInReverseSearch;
}
return { reverseSearch };
}
module.exports = {
REPL_MODE_SLOPPY: Symbol('repl-sloppy'),
REPL_MODE_STRICT,
isRecoverableError,
kStandaloneREPL: Symbol('kStandaloneREPL'),
setupPreview,
setupReverseSearch
};
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