errors: consistent format for error messages

lib/internal/errors.js

@@ -1,5 +1,6 @@
 /* eslint documented-errors: "error" */
 /* eslint alphabetize-errors: "error" */
+/* eslint prefer-util-format-errors: "error" */
 
 'use strict';
 
@@ -222,8 +223,8 @@ module.exports = exports = {
 
 E('ERR_ARG_NOT_ITERABLE', '%s must be iterable');
 E('ERR_ASSERTION', '%s');
-E('ERR_ASYNC_CALLBACK', (name) => `${name} must be a function`);
-E('ERR_ASYNC_TYPE', (s) => `Invalid name for async "type": ${s}`);
+E('ERR_ASYNC_CALLBACK', '%s must be a function');
+E('ERR_ASYNC_TYPE', 'Invalid name for async "type": %s');
 E('ERR_BUFFER_OUT_OF_BOUNDS', bufferOutOfBounds);
 E('ERR_BUFFER_TOO_LARGE',
   `Cannot create a Buffer larger than 0x${kMaxLength.toString(16)} bytes`);
@@ -245,12 +246,10 @@ E('ERR_CRYPTO_INVALID_STATE', 'Invalid state for operation %s');
 E('ERR_CRYPTO_SIGN_KEY_REQUIRED', 'No key provided to sign');
 E('ERR_CRYPTO_TIMING_SAFE_EQUAL_LENGTH',
   'Input buffers must have the same length');
-E('ERR_DNS_SET_SERVERS_FAILED', (err, servers) =>
-  `c-ares failed to set servers: "${err}" [${servers}]`);
+E('ERR_DNS_SET_SERVERS_FAILED', 'c-ares failed to set servers: "%s" [%s]');
 E('ERR_ENCODING_INVALID_ENCODED_DATA',
-  (enc) => `The encoded data was not valid for encoding ${enc}`);
-E('ERR_ENCODING_NOT_SUPPORTED',
-  (enc) => `The "${enc}" encoding is not supported`);
+  'The encoded data was not valid for encoding %s');
+E('ERR_ENCODING_NOT_SUPPORTED', 'The "%s" encoding is not supported');
 E('ERR_FALSY_VALUE_REJECTION', 'Promise was rejected with falsy value');
 E('ERR_HTTP2_CONNECT_AUTHORITY',
   ':authority header is required for CONNECT requests');
@@ -270,10 +269,9 @@ E('ERR_HTTP2_HEADERS_AFTER_RESPOND',
   'Cannot specify additional headers after response initiated');
 E('ERR_HTTP2_HEADERS_OBJECT', 'Headers must be an object');
 E('ERR_HTTP2_HEADERS_SENT', 'Response has already been initiated.');
-E('ERR_HTTP2_HEADER_REQUIRED',
-  (name) => `The ${name} header is required`);
+E('ERR_HTTP2_HEADER_REQUIRED', 'The %s header is required');
 E('ERR_HTTP2_HEADER_SINGLE_VALUE',
-  (name) => `Header field "${name}" must have only a single value`);
+  'Header field "%s" must have only a single value');
 E('ERR_HTTP2_INFO_HEADERS_AFTER_RESPOND',
   'Cannot send informational headers after the HTTP message has been sent');
 E('ERR_HTTP2_INFO_STATUS_NOT_ALLOWED',
@@ -282,44 +280,40 @@ E('ERR_HTTP2_INVALID_CONNECTION_HEADERS',
   'HTTP/1 Connection specific headers are forbidden: "%s"');
 E('ERR_HTTP2_INVALID_HEADER_VALUE', 'Invalid value "%s" for header "%s"');
 E('ERR_HTTP2_INVALID_INFO_STATUS',
-  (code) => `Invalid informational status code: ${code}`);
+  'Invalid informational status code: %s');
 E('ERR_HTTP2_INVALID_PACKED_SETTINGS_LENGTH',
   'Packed settings length must be a multiple of six');
 E('ERR_HTTP2_INVALID_PSEUDOHEADER',
-  (name) => `"${name}" is an invalid pseudoheader or is used incorrectly`);
+  '"%s" is an invalid pseudoheader or is used incorrectly');
 E('ERR_HTTP2_INVALID_SESSION', 'The session has been destroyed');
 E('ERR_HTTP2_INVALID_SETTING_VALUE',
-  (name, value) => `Invalid value for setting "${name}": ${value}`);
+  'Invalid value for setting "%s": %s');
 E('ERR_HTTP2_INVALID_STREAM', 'The stream has been destroyed');
 E('ERR_HTTP2_MAX_PENDING_SETTINGS_ACK',
-  (max) => `Maximum number of pending settings acknowledgements (${max})`);
+  'Maximum number of pending settings acknowledgements (%s)');
 E('ERR_HTTP2_NO_SOCKET_MANIPULATION',
   'HTTP/2 sockets should not be directly manipulated (e.g. read and written)');
 E('ERR_HTTP2_OUT_OF_STREAMS',
   'No stream ID is available because maximum stream ID has been reached');
 E('ERR_HTTP2_PAYLOAD_FORBIDDEN',
-  (code) => `Responses with ${code} status must not have a payload`);
+  'Responses with %s status must not have a payload');
 E('ERR_HTTP2_PSEUDOHEADER_NOT_ALLOWED', 'Cannot set HTTP/2 pseudo-headers');
 E('ERR_HTTP2_PUSH_DISABLED', 'HTTP/2 client has disabled push streams');
 E('ERR_HTTP2_SEND_FILE', 'Only regular files can be sent');
 E('ERR_HTTP2_SOCKET_BOUND',
   'The socket is already bound to an Http2Session');
 E('ERR_HTTP2_STATUS_101',
   'HTTP status code 101 (Switching Protocols) is forbidden in HTTP/2');
-E('ERR_HTTP2_STATUS_INVALID',
-  (code) => `Invalid status code: ${code}`);
+E('ERR_HTTP2_STATUS_INVALID', 'Invalid status code: %s');
 E('ERR_HTTP2_STREAM_CLOSED', 'The stream is already closed');
-E('ERR_HTTP2_STREAM_ERROR',
-  (code) => `Stream closed with error code ${code}`);
+E('ERR_HTTP2_STREAM_ERROR', 'Stream closed with error code %s');
 E('ERR_HTTP2_STREAM_SELF_DEPENDENCY', 'A stream cannot depend on itself');
-E('ERR_HTTP2_UNSUPPORTED_PROTOCOL',
-  (protocol) => `protocol "${protocol}" is unsupported.`);
+E('ERR_HTTP2_UNSUPPORTED_PROTOCOL', 'protocol "%s" is unsupported.');
 E('ERR_HTTP_HEADERS_SENT',
   'Cannot %s headers after they are sent to the client');
 E('ERR_HTTP_INVALID_CHAR', 'Invalid character in statusMessage.');
 E('ERR_HTTP_INVALID_HEADER_VALUE', 'Invalid value "%s" for header "%s"');
-E('ERR_HTTP_INVALID_STATUS_CODE',
-  (originalStatusCode) => `Invalid status code: ${originalStatusCode}`);
+E('ERR_HTTP_INVALID_STATUS_CODE', 'Invalid status code: %s');
 E('ERR_HTTP_TRAILER_INVALID',
   'Trailers are invalid with this transfer encoding');
 E('ERR_INDEX_OUT_OF_RANGE', 'Index out of range');
@@ -328,16 +322,14 @@ E('ERR_INSPECTOR_CLOSED', 'Session was closed');
 E('ERR_INSPECTOR_NOT_AVAILABLE', 'Inspector is not available');
 E('ERR_INSPECTOR_NOT_CONNECTED', 'Session is not connected');
 E('ERR_INVALID_ARG_TYPE', invalidArgType);
-E('ERR_INVALID_ARG_VALUE',
-  (name, value) => {
-    return `The value "${String(value)}" is invalid for argument "${name}"`;
-  });
+E('ERR_INVALID_ARG_VALUE', (name, value) =>
+  `The value "${String(value)}" is invalid for argument "${name}"`);
 E('ERR_INVALID_ARRAY_LENGTH',
   (name, len, actual) => {
     internalAssert(typeof actual === 'number', 'actual must be a number');
     return `The array "${name}" (length ${actual}) must be of length ${len}.`;
   });
-E('ERR_INVALID_ASYNC_ID', (type, id) => `Invalid ${type} value: ${id}`);
+E('ERR_INVALID_ASYNC_ID', 'Invalid %s value: %s');
 E('ERR_INVALID_BUFFER_SIZE', 'Buffer size must be a multiple of %s');
 E('ERR_INVALID_CALLBACK', 'Callback must be a function');
 E('ERR_INVALID_CHAR', invalidChar);
@@ -352,15 +344,12 @@ E('ERR_INVALID_FILE_URL_PATH', 'File URL path %s');
 E('ERR_INVALID_HANDLE_TYPE', 'This handle type cannot be sent');
 E('ERR_INVALID_HTTP_TOKEN', '%s must be a valid HTTP token ["%s"]');
 E('ERR_INVALID_IP_ADDRESS', 'Invalid IP address: %s');
-E('ERR_INVALID_OPT_VALUE',
-  (name, value) => {
-    return `The value "${String(value)}" is invalid for option "${name}"`;
-  });
+E('ERR_INVALID_OPT_VALUE', (name, value) =>
+  `The value "${String(value)}" is invalid for option "${name}"`);
 E('ERR_INVALID_OPT_VALUE_ENCODING',
-  (value) => `The value "${String(value)}" is invalid for option "encoding"`);
+  'The value "%s" is invalid for option "encoding"');
 E('ERR_INVALID_PERFORMANCE_MARK', 'The "%s" performance mark has not been set');
-E('ERR_INVALID_PROTOCOL', (protocol, expectedProtocol) =>
-  `Protocol "${protocol}" not supported. Expected "${expectedProtocol}"`);
+E('ERR_INVALID_PROTOCOL', 'Protocol "%s" not supported. Expected "%s"');
 E('ERR_INVALID_REPL_EVAL_CONFIG',
   'Cannot specify both "breakEvalOnSigint" and "eval" for REPL');
 E('ERR_INVALID_SYNC_FORK_INPUT',
@@ -400,8 +389,7 @@ E('ERR_SOCKET_BAD_BUFFER_SIZE', 'Buffer size must be a positive integer');
 E('ERR_SOCKET_BAD_PORT', 'Port should be > 0 and < 65536. Received %s.');
 E('ERR_SOCKET_BAD_TYPE',
   'Bad socket type specified. Valid types are: udp4, udp6');
-E('ERR_SOCKET_BUFFER_SIZE',
-  (reason) => `Could not get or set buffer size: ${reason}`);
+E('ERR_SOCKET_BUFFER_SIZE', 'Could not get or set buffer size: %s');
 E('ERR_SOCKET_CANNOT_SEND', 'Unable to send data');
 E('ERR_SOCKET_CLOSED', 'Socket is closed');
 E('ERR_SOCKET_DGRAM_NOT_RUNNING', 'Not running');
@@ -417,8 +405,7 @@ E('ERR_STREAM_WRITE_AFTER_END', 'write after end');
 E('ERR_SYSTEM_ERROR', sysError('A system error occurred'));
 E('ERR_TLS_CERT_ALTNAME_INVALID',
   'Hostname/IP does not match certificate\'s altnames: %s');
-E('ERR_TLS_DH_PARAM_SIZE', (size) =>
-  `DH parameter size ${size} is less than 2048`);
+E('ERR_TLS_DH_PARAM_SIZE', 'DH parameter size %s is less than 2048');
 E('ERR_TLS_HANDSHAKE_TIMEOUT', 'TLS handshake timeout');
 E('ERR_TLS_RENEGOTIATION_FAILED', 'Failed to renegotiate');
 E('ERR_TLS_REQUIRED_SERVER_NAME',
@@ -428,8 +415,7 @@ E('ERR_TRANSFORM_ALREADY_TRANSFORMING',
   'Calling transform done when still transforming');
 E('ERR_TRANSFORM_WITH_LENGTH_0',
   'Calling transform done when writableState.length != 0');
-E('ERR_UNESCAPED_CHARACTERS',
-  (name) => `${name} contains unescaped characters`);
+E('ERR_UNESCAPED_CHARACTERS', '%s contains unescaped characters');
 E('ERR_UNHANDLED_ERROR',
   (err) => {
     const msg = 'Unhandled error.';

test/parallel/test-eslint-prefer-util-format-errors.js

@@ -0,0 +1,27 @@
+'use strict';
+
+/* eslint-disable no-template-curly-in-string */
+
+require('../common');
+
+const RuleTester = require('../../tools/eslint').RuleTester;
+const rule = require('../../tools/eslint-rules/prefer-util-format-errors');
+
+new RuleTester({ parserOptions: { ecmaVersion: 6 } })
+  .run('prefer-util-format-errors', rule, {
+    valid: [
+      'E(\'ABC\', \'abc\');',
+      'E(\'ABC\', (arg1, arg2) => `${arg2}${arg1}`);',
+      'E(\'ABC\', (arg1, arg2) => `${arg1}{arg2.something}`);',
+      'E(\'ABC\', (arg1, arg2) => fn(arg1, arg2));'
+    ],
+    invalid: [
+      {
+        code: 'E(\'ABC\', (arg1, arg2) => `${arg1}${arg2}`);',
+        errors: [{
+          message: 'Please use a printf-like formatted string that ' +
+                   'util.format can consume.'
+        }]
+      }
+    ]
+  });

tools/eslint-rules/prefer-util-format-errors.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const errMsg = 'Please use a printf-like formatted string that util.format' +
+               ' can consume.';
+
+function isArrowFunctionWithTemplateLiteral(node) {
+  return node.type === 'ArrowFunctionExpression' &&
+         node.body.type === 'TemplateLiteral';
+}
+
+function isDefiningError(node) {
+  return node.expression &&
+         node.expression.type === 'CallExpression' &&
+         node.expression.callee &&
+         node.expression.callee.name === 'E';
+}
+
+module.exports = {
+  create: function(context) {
+    return {
+      ExpressionStatement: function(node) {
+        if (!isDefiningError(node))
+          return;
+
+        const msg = node.expression.arguments[1];
+        if (!isArrowFunctionWithTemplateLiteral(msg))
+          return;
+
+        const { expressions } = msg.body;
+        const hasSequentialPar