diff options
Diffstat (limited to '')
-rw-r--r-- | devtools/server/actors/webconsole/commands/parser.js | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/devtools/server/actors/webconsole/commands/parser.js b/devtools/server/actors/webconsole/commands/parser.js new file mode 100644 index 0000000000..49a7a5a1d7 --- /dev/null +++ b/devtools/server/actors/webconsole/commands/parser.js @@ -0,0 +1,249 @@ +/* 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"; + +loader.lazyRequireGetter( + this, + ["WebConsoleCommandsManager"], + "resource://devtools/server/actors/webconsole/commands/manager.js", + true +); + +const COMMAND = "command"; +const KEY = "key"; +const ARG = "arg"; + +const COMMAND_PREFIX = /^:/; +const KEY_PREFIX = /^--/; + +// default value for flags +const DEFAULT_VALUE = true; +const COMMAND_DEFAULT_FLAG = { + block: "url", + screenshot: "filename", + unblock: "url", +}; + +/** + * When given a string that begins with `:` and a unix style string, + * returns the command name and the arguments. + * Throws if the command doesn't exist. + * This is intended to be used by the WebConsole actor only. + * + * @param String string + * A string to format that begins with `:`. + * + * @returns Object The command name and the arguments + * { command: String, args: Object } + */ +function getCommandAndArgs(string) { + if (!isCommand(string)) { + throw Error("getCommandAndArgs was called without `:`"); + } + string = string.trim(); + if (string === ":") { + throw Error("Missing a command name after ':'"); + } + const tokens = string.split(/\s+/).map(createToken); + return parseCommand(tokens); +} + +/** + * creates a token object depending on a string which as a prefix, + * either `:` for a command or `--` for a key, or nothing for an argument + * + * @param String string + * A string to use as the basis for the token + * + * @returns Object Token Object, with the following shape + * { type: String, value: String } + */ +function createToken(string) { + if (isCommand(string)) { + const value = string.replace(COMMAND_PREFIX, ""); + if (!value) { + throw Error("Missing a command name after ':'"); + } + if (!WebConsoleCommandsManager.getAllColonCommandNames().includes(value)) { + throw Error(`'${value}' is not a valid command`); + } + return { type: COMMAND, value }; + } + if (isKey(string)) { + const value = string.replace(KEY_PREFIX, ""); + if (!value) { + throw Error("invalid flag"); + } + return { type: KEY, value }; + } + return { type: ARG, value: string }; +} + +/** + * returns a command Tree object for a set of tokens + * + * + * @param Array Tokens tokens + * An array of Token objects + * + * @returns Object Tree Object, with the following shape + * { command: String, args: Object } + */ +function parseCommand(tokens) { + let command = null; + const args = {}; + + for (let i = 0; i < tokens.length; i++) { + const token = tokens[i]; + if (token.type === COMMAND) { + if (command) { + // we are throwing here because two commands have been passed and it is unclear + // what the user's intention was + throw Error( + "Executing multiple commands in one evaluation is not supported" + ); + } + command = token.value; + } + + if (token.type === KEY) { + const nextTokenIndex = i + 1; + const nextToken = tokens[nextTokenIndex]; + let values = args[token.value] || DEFAULT_VALUE; + if (nextToken && nextToken.type === ARG) { + const { value, offset } = collectString( + nextToken, + tokens, + nextTokenIndex + ); + // in order for JSON.stringify to correctly output values, they must be correctly + // typed + // As per the old GCLI documentation, we can only have one value associated with a + // flag but multiple flags with the same name can exist and should be combined + // into and array. Here we are associating only the value on the right hand + // side if it is of type `arg` as a single value; the second case initializes + // an array, and the final case pushes a value to an existing array + const typedValue = getTypedValue(value); + if (values === DEFAULT_VALUE) { + values = typedValue; + } else if (!Array.isArray(values)) { + values = [values, typedValue]; + } else { + values.push(typedValue); + } + // skip the next token since we have already consumed it + i = nextTokenIndex + offset; + } + args[token.value] = values; + } + + // Since this has only been implemented for screenshot, we can only have one default + // value. Eventually we may have more default values. For now, ignore multiple + // unflagged args + const defaultFlag = COMMAND_DEFAULT_FLAG[command]; + if (token.type === ARG && !args[defaultFlag]) { + const { value, offset } = collectString(token, tokens, i); + // Throw if the command isn't registered in COMMAND_DEFAULT_FLAG + // as this command may not expect any argument without an explicit argument name like "-name arg" + if (!defaultFlag) { + throw new Error( + `:${command} command doesn't support unnamed '${value}' argument.` + ); + } + args[defaultFlag] = getTypedValue(value); + i = i + offset; + } + } + return { command, args }; +} + +const stringChars = ['"', "'", "`"]; +function isStringChar(testChar) { + return stringChars.includes(testChar); +} + +function checkLastChar(string, testChar) { + const lastChar = string[string.length - 1]; + return lastChar === testChar; +} + +function hasUnescapedChar(value, char, rightOffset, leftOffset) { + const lastPos = value.length - 1; + const string = value.slice(rightOffset, lastPos - leftOffset); + const index = string.indexOf(char); + if (index === -1) { + return false; + } + const prevChar = index > 0 ? string[index - 1] : null; + // return false if the unexpected character is escaped, true if it is not + return prevChar !== "\\"; +} + +function collectString(token, tokens, index) { + const firstChar = token.value[0]; + const isString = isStringChar(firstChar); + const UNESCAPED_CHAR_ERROR = segment => + `String has unescaped \`${firstChar}\` in [${segment}...],` + + " may miss a space between arguments"; + let value = token.value; + + // the test value is not a string, or it is a string but a complete one + // i.e. `"test"`, as opposed to `"foo`. In either case, this we can return early + if (!isString || checkLastChar(value, firstChar)) { + return { value, offset: 0 }; + } + + if (hasUnescapedChar(value, firstChar, 1, 0)) { + throw Error(UNESCAPED_CHAR_ERROR(value)); + } + + let offset = null; + for (let i = index + 1; i <= tokens.length; i++) { + if (i === tokens.length) { + throw Error("String does not terminate"); + } + + const nextToken = tokens[i]; + if (nextToken.type !== ARG) { + throw Error(`String does not terminate before flag "${nextToken.value}"`); + } + + value = `${value} ${nextToken.value}`; + + if (hasUnescapedChar(nextToken.value, firstChar, 0, 1)) { + throw Error(UNESCAPED_CHAR_ERROR(value)); + } + + if (checkLastChar(nextToken.value, firstChar)) { + offset = i - index; + break; + } + } + return { value, offset }; +} + +function isCommand(string) { + return COMMAND_PREFIX.test(string); +} + +function isKey(string) { + return KEY_PREFIX.test(string); +} + +function getTypedValue(value) { + if (!isNaN(value)) { + return Number(value); + } + if (value === "true" || value === "false") { + return Boolean(value); + } + if (isStringChar(value[0])) { + return value.slice(1, value.length - 1); + } + return value; +} + +exports.getCommandAndArgs = getCommandAndArgs; +exports.isCommand = isCommand; |