diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el index 5a4f383..c0e5655 100644 --- a/lisp/progmodes/js.el +++ b/lisp/progmodes/js.el @@ -52,6 +52,7 @@ (require 'imenu) (require 'moz nil t) (require 'json nil t) +(require 'sgml-mode) (eval-when-compile (require 'cl-lib) @@ -551,6 +552,18 @@ don't indent the first one's initializer; otherwise, indent it. :safe 'symbolp :group 'js) +(defcustom js-indent-jsx nil + "Non-nil to indent JSX elements. + +`sgml-basic-offset' and `sgml-attribute-offset' determine the +indentation level of lines containing JSX. + +Enabling this may slow down indentation of entire large files." + :version "25.1" + :type 'boolean + :safe 'booleanp + :group 'js) + ;;; KeyMap (defvar js-mode-map @@ -1998,9 +2011,195 @@ indentation is aligned to that column." (+ js-indent-level js-expr-indent-offset)) (t 0)))) -(defun js-indent-line () +;;; JSX Indentation + +(defsubst js--jsx-find-before-tag () + "Find where JSX starts. + +Assume JSX appears in the following instances: +- Inside parentheses, when returned or as the first argument + to a function, and after a newline +- When assigned to variables or object properties, but only + on a single line +- As the N+1th argument to a function + +This is an optimized version of (re-search-backward \"[(,]\n\" +nil t), except set point to the end of the match. This logic +executes up to the number of lines in the file, so it should be +really fast to reduce that impact." + (let (pos) + (while (and (> (point) (point-min)) + (not (progn + (end-of-line 0) + (when (or (eq (char-before) 40) ; ( + (eq (char-before) 44)) ; , + (setq pos (1- (point)))))))) + pos)) + +(defconst js--jsx-end-tag-re + (concat "\\|/>") + "Find the end of a JSX element.") + +(defconst js--jsx-after-tag-re "[),]" + "Find where JSX ends. +This complements the assumption of where JSX appears from +`js--jsx-before-tag-re', which see.") + +(defun js--jsx-indented-element-p () + "Determine if/how the current line should be indented as JSX. + +Return `first' for the first JSXElement on its own line. +Return `nth' for subsequent lines of the first JSXElement. +Return `expression' for an embedded JS expression. +Return `after' for anything after the last JSXElement. +Return nil for non-JSX lines. + +Currently, JSX indentation supports the following styles: + +- Single-line elements (indented like normal JS): + + var element =
; + +- Multi-line elements (enclosed in parentheses): + + function () { + return ( +
+
+
+ ); + } + +- Function arguments: + + React.render( +
, + document.querySelector('.root') + );" + (let ((current-pos (point)) + (current-line (line-number-at-pos)) + last-pos + before-tag-pos before-tag-line + tag-start-pos tag-start-line + tag-end-pos tag-end-line + after-tag-line + parens paren type) + (save-excursion + (and + ;; Determine if we're inside a jsx element + (progn + (end-of-line) + (while (and (not tag-start-pos) + (setq last-pos (js--jsx-find-before-tag))) + (while (forward-comment 1)) + (when (= (char-after) 60) ; < + (setq before-tag-pos last-pos + tag-start-pos (point))) + (goto-char last-pos)) + tag-start-pos) + (progn + (setq before-tag-line (line-number-at-pos before-tag-pos) + tag-start-line (line-number-at-pos tag-start-pos)) + (and + ;; A "before" line which also starts an element begins with js, so + ;; indent it like js + (> current-line before-tag-line) + ;; Only indent the jsx lines like jsx + (>= current-line tag-start-line))) + (cond + ;; Analyze bounds if there are any + ((progn + (while (and (not tag-end-pos) + (setq last-pos (re-search-forward js--jsx-end-tag-re nil t))) + (while (forward-comment 1)) + (when (looking-at js--jsx-after-tag-re) + (setq tag-end-pos last-pos))) + tag-end-pos) + (setq tag-end-line (line-number-at-pos tag-end-pos) + after-tag-line (line-number-at-pos after-tag-line)) + (or (and + ;; Ensure we're actually within the bounds of the jsx + (<= current-line tag-end-line) + ;; An "after" line which does not end an element begins with + ;; js, so indent it like js + (<= current-line after-tag-line)) + (and + ;; Handle another case where there could be e.g. comments after + ;; the element + (> current-line tag-end-line) + (< current-line after-tag-line) + (setq type 'after)))) + ;; They may not be any bounds (yet) + (t)) + ;; Check if we're inside an embedded multi-line js expression + (cond + ((not type) + (goto-char current-pos) + (end-of-line) + (setq parens (nth 9 (syntax-ppss))) + (while (and parens (not type)) + (setq paren (car parens)) + (cond + ((and (>= paren tag-start-pos) + ;; Curly bracket indicates the start of an embedded expression + (= (char-after paren) 123) ; { + ;; The first line of the expression is indented like sgml + (> current-line (line-number-at-pos paren)) + ;; Check if within a closing curly bracket (if any) + ;; (exclusive, as the closing bracket is indented like sgml) + (cond + ((progn + (goto-char paren) + (ignore-errors (let (forward-sexp-function) + (forward-sexp)))) + (< current-line (line-number-at-pos))) + (t))) + ;; Indicate this guy will be indented specially + (setq type 'expression)) + (t (setq parens (cdr parens))))) + t) + (t)) + (cond + (type) + ;; Indent the first jsx thing like js so we can indent future jsx things + ;; like sgml relative to the first thing + ((= current-line tag-start-line) 'first) + ('nth)))))) + +(defmacro js--as-sgml (&rest body) + "Execute BODY as if in sgml-mode." + `(with-syntax-table sgml-mode-syntax-table + (let (forward-sexp-function + parse-sexp-lookup-properties) + ,@body))) + +(defun js--expression-in-sgml-indent-line () + "Indent the current line as JavaScript or SGML (whichever is farther)." + (let* (indent-col + (savep (point)) + ;; Don't whine about errors/warnings when we're indenting. + ;; This has to be set before calling parse-partial-sexp below. + (inhibit-point-motion-hooks t) + (parse-status (save-excursion + (syntax-ppss (point-at-bol))))) + ;; Don't touch multiline strings. + (unless (nth 3 parse-status) + (setq indent-col (save-excursion + (back-to-indentation) + (if (>= (point) savep) (setq savep nil)) + (js--as-sgml (sgml-calculate-indent)))) + (if (null indent-col) + 'noindent + ;; Use whichever indentation column is greater, such that the sgml + ;; column is effectively a minimum + (setq indent-col (max (js--proper-indentation parse-status) + (+ indent-col js-indent-level))) + (if savep + (save-excursion (indent-line-to indent-col)) + (indent-line-to indent-col)))))) + +(defun js--indent-line-as-js () "Indent the current line as JavaScript." - (interactive) (let* ((parse-status (save-excursion (syntax-ppss (point-at-bol)))) (offset (- (point) (save-excursion (back-to-indentation) (point))))) @@ -2008,6 +2207,29 @@ indentation is aligned to that column." (indent-line-to (js--proper-indentation parse-status)) (when (> offset 0) (forward-char offset))))) +(defun js-indent-line () + "Indent the current line as JavaScript or JSX source text. +If `js-indent-jsx' is non-nil, which see, indent the current line +as JSX source text." + (interactive) + (cond + (js-indent-jsx + (let ((indentation-type (js--jsx-indented-element-p))) + (cond + ((eq indentation-type 'expression) + (js--expression-in-sgml-indent-line)) + ((or (eq indentation-type 'first) + (eq indentation-type 'after)) + ;; Don't treat this first thing as a continued expression (often a "<" or + ;; ">" causes this misinterpretation) + (cl-letf (((symbol-function #'js--continued-expression-p) 'ignore)) + (js--indent-line-as-js))) + ((eq indentation-type 'nth) + (js--as-sgml (sgml-indent-line))) + (t (js--indent-line-as-js))))) + (t + (js--indent-line-as-js)))) + ;;; Filling (defvar js--filling-paragraph nil) diff --git a/test/indent/js-indent-jsx.js b/test/indent/js-indent-jsx.js new file mode 100644 index 0000000..1ea65ed --- /dev/null +++ b/test/indent/js-indent-jsx.js @@ -0,0 +1,84 @@ +var foo =
; + +return ( +
+
+
+
+
+
+
+
+); + +React.render( +
+
+
, + { + a: 1 + }, +
+
+
+); + +return ( + // Sneaky! +
+); + +return ( +
+ // Sneaky! +); + +React.render( + , + { + a: 1 + } +); + +return ( +
+ {array.map(function () { + return { + a: 1 + }; + })} +
+); + +return ( +
+
+); + +// Local Variables: +// indent-tabs-mode: nil +// js-indent-level: 2 +// js-indent-jsx: t +// End: + +// The following test has intentionally unclosed elements and should +// be placed below all other tests to prevent awkward indentation. + +return ( +
+ {array.map(function () { + return { + a: 1