;;; rust-mode-tests.el --- ERT tests for rust-mode.el

(require 'rust-mode)
(require 'ert)
(require 'cl)

(setq rust-test-fill-column 32)

(defun rust-compare-code-after-manip (original point-pos manip-func expected got)
  (equal expected got))

(defun rust-test-explain-bad-manip (original point-pos manip-func expected got)
  (if (equal expected got)
      nil
    (list
     ;; The (goto-char) and (insert) business here is just for
     ;; convenience--after an error, you can copy-paste that into emacs eval to
     ;; insert the bare strings into a buffer
     "Rust code was manipulated wrong after:"
     `(insert ,original)
     `(goto-char ,point-pos)
     'expected `(insert ,expected)
     'got `(insert ,got)
     (loop for i from 0 to (max (length original) (length expected))
           for oi = (if (< i (length got)) (elt got i))
           for ei = (if (< i (length expected)) (elt expected i))
           while (equal oi ei)
           finally return `(first-difference-at
                            (goto-char ,(+ 1 i))
                            expected ,(char-to-string ei)
                            got ,(char-to-string oi))))))
(put 'rust-compare-code-after-manip 'ert-explainer
     'rust-test-explain-bad-manip)

(defun rust-test-manip-code (original point-pos manip-func expected)
  (with-temp-buffer
    (rust-mode)
    (insert original)
    (goto-char point-pos)
    (funcall manip-func)
    (should (rust-compare-code-after-manip
             original point-pos manip-func expected (buffer-string)))))

(defun test-fill-paragraph (unfilled expected &optional start-pos end-pos)
  "We're going to run through many scenarios here--the point should be able to be anywhere from the start-pos (defaults to 1) through end-pos (defaults to the length of what was passed in) and (fill-paragraph) should return the same result.

Also, the result should be the same regardless of whether the code is at the beginning or end of the file.  (If you're not careful, that can make a difference.)  So we test each position given above with the passed code at the beginning, the end, neither and both.  So we do this a total of (end-pos - start-pos)*4 times.  Oy."
  (let* ((start-pos (or start-pos 1))
         (end-pos (or end-pos (length unfilled)))
         (padding "\n     \n")
         (padding-len (length padding)))
    (loop
     for pad-at-beginning from 0 to 1
     do (loop for pad-at-end from 0 to 1
              with padding-beginning = (if (= 0 pad-at-beginning) "" padding)
              with padding-end = (if (= 0 pad-at-end) "" padding)
              with padding-adjust = (* padding-len pad-at-beginning)
              with padding-beginning = (if (= 0 pad-at-beginning) "" padding)
              with padding-end = (if (= 0 pad-at-end) "" padding)
              ;; If we're adding space to the beginning, and our start position
              ;; is at the very beginning, we want to test within the added space.
              ;; Otherwise adjust the start and end for the beginning padding.
              with start-pos = (if (= 1 start-pos) 1 (+ padding-adjust start-pos))
              with end-pos = (+ end-pos padding-adjust)
              do (loop for pos from start-pos to end-pos
                       do (rust-test-manip-code
                           (concat padding-beginning unfilled padding-end)
                           pos
                           (lambda ()
                             (let ((fill-column rust-test-fill-column))
                               (fill-paragraph)))
                           (concat padding-beginning expected padding-end)))))))

(ert-deftest fill-paragraph-top-level-multi-line-style-doc-comment-second-line ()
  (test-fill-paragraph
   "/**
 * This is a very very very very very very very long string
 */"
   "/**
 * This is a very very very very
 * very very very long string
 */"))


(ert-deftest fill-paragraph-top-level-multi-line-style-doc-comment-first-line ()
  (test-fill-paragraph
   "/** This is a very very very very very very very long string
 */"
   "/** This is a very very very
 * very very very very long
 * string
 */"))

(ert-deftest fill-paragraph-multi-paragraph-multi-line-style-doc-comment ()
  (let
      ((multi-paragraph-unfilled
        "/**
 * This is the first really really really really really really really long paragraph
 *
 * This is the second really really really really really really long paragraph
 */"))
    (test-fill-paragraph
     multi-paragraph-unfilled
     "/**
 * This is the first really
 * really really really really
 * really really long paragraph
 *
 * This is the second really really really really really really long paragraph
 */"
     1 89)
    (test-fill-paragraph
     multi-paragraph-unfilled
     "/**
 * This is the first really really really really really really really long paragraph
 *
 * This is the second really
 * really really really really
 * really long paragraph
 */"
     90)))

(ert-deftest fill-paragraph-multi-paragraph-single-line-style-doc-comment ()
  (let
      ((multi-paragraph-unfilled
        "/// This is the first really really really really really really really long paragraph
///
/// This is the second really really really really really really long paragraph"))
    (test-fill-paragraph
     multi-paragraph-unfilled
     "/// This is the first really
/// really really really really
/// really really long paragraph
///
/// This is the second really really really really really really long paragraph"
     1 86)
    (test-fill-paragraph
     multi-paragraph-unfilled
     "/// This is the first really really really really really really really long paragraph
///
/// This is the second really
/// really really really really
/// really long paragraph"
     87)))

(ert-deftest fill-paragraph-multi-paragraph-single-line-style-indented ()
  (test-fill-paragraph
   "     // This is the first really really really really really really really long paragraph
     //
     // This is the second really really really really really really long paragraph"
   "     // This is the first really
     // really really really
     // really really really
     // long paragraph
     //
     // This is the second really really really really really really long paragraph" 1 89))

(ert-deftest fill-paragraph-multi-line-style-inner-doc-comment ()
  (test-fill-paragraph
   "/*! This is a very very very very very very very long string
 */"
   "/*! This is a very very very
 * very very very very long
 * string
 */"))

(ert-deftest fill-paragraph-single-line-style-inner-doc-comment ()
  (test-fill-paragraph
   "//! This is a very very very very very very very long string"
   "//! This is a very very very
//! very very very very long
//! string"))

(ert-deftest fill-paragraph-prefixless-multi-line-doc-comment ()
  (test-fill-paragraph
   "/**
This is my summary. Blah blah blah blah blah. Dilly dally dilly dally dilly dally doo.

This is some more text.  Fee fie fo fum.  Humpty dumpty sat on a wall.
*/"
   "/**
This is my summary. Blah blah
blah blah blah. Dilly dally
dilly dally dilly dally doo.

This is some more text.  Fee fie fo fum.  Humpty dumpty sat on a wall.
*/" 4 90))

(ert-deftest fill-paragraph-with-no-space-after-star-prefix ()
  (test-fill-paragraph
   "/**
 *This is a very very very very very very very long string
 */"
   "/**
 *This is a very very very very
 *very very very long string
 */"))

(ert-deftest fill-paragraph-single-line-style-with-code-before ()
  (test-fill-paragraph
   "fn foo() { }
/// This is my comment.  This is more of my comment.  This is even more."
   "fn foo() { }
/// This is my comment.  This is
/// more of my comment.  This is
/// even more." 14))

(ert-deftest fill-paragraph-single-line-style-with-code-after ()
  (test-fill-paragraph
   "/// This is my comment.  This is more of my comment.  This is even more.
fn foo() { }"
   "/// This is my comment.  This is
/// more of my comment.  This is
/// even more.
fn foo() { }" 1 73))

(ert-deftest fill-paragraph-single-line-style-code-before-and-after ()
  (test-fill-paragraph
   "fn foo() { }
/// This is my comment.  This is more of my comment.  This is even more.
fn bar() { }"
   "fn foo() { }
/// This is my comment.  This is
/// more of my comment.  This is
/// even more.
fn bar() { }" 14 67))

(defun test-auto-fill (initial position inserted expected)
  (rust-test-manip-code
   initial
   position
   (lambda ()
     (unwind-protect
         (progn
           (let ((fill-column rust-test-fill-column))
             (auto-fill-mode)
             (goto-char position)
             (insert inserted)
             (syntax-ppss-flush-cache 1)
             (funcall auto-fill-function)))
       (auto-fill-mode t)))
   expected))

(ert-deftest auto-fill-multi-line-doc-comment ()
  (test-auto-fill
   "/**
 *
 */"
   7
   " This is a very very very very very very very long string"
   "/**
 * This is a very very very very
 * very very very long string
 */"))

(ert-deftest auto-fill-single-line-doc-comment ()
  (test-auto-fill
   "/// This is the first really
/// really really really really
/// really really long paragraph
///
/// "
   103
   "This is the second really really really really really really long paragraph"
   "/// This is the first really
/// really really really really
/// really really long paragraph
///
/// This is the second really
/// really really really really
/// really long paragraph"
   ))

(ert-deftest auto-fill-multi-line-prefixless ()
  (test-auto-fill
   "/*

 */"
   4
   "This is a very very very very very very very long string"
   "/*
This is a very very very very
very very very long string
 */"
   ))

(defun test-indent (indented)
  (let ((deindented (replace-regexp-in-string "^[[:blank:]]*" "      " indented)))
    (rust-test-manip-code
     deindented
     1
     (lambda ()
       ;; The indentation will fail in some cases if the syntax properties are
       ;; not set.  This only happens when font-lock fontifies the buffer.
       (font-lock-fontify-buffer)
       (indent-region 1 (+ 1 (buffer-size))))
     indented)))


(ert-deftest indent-struct-fields-aligned ()
  (test-indent
   "
struct Foo { bar: int,
             baz: int }

struct Blah {x:int,
             y:int,
             z:String"))

(ert-deftest indent-doc-comments ()
  (test-indent
   "
/**
 * This is a doc comment
 *
 */

/// So is this

fn foo() {
    /*!
     * this is a nested doc comment
     */
    \n    //! And so is this
}"))

(ert-deftest indent-inside-braces ()
  (test-indent
   "
// struct fields out one level:
struct foo {
    a:int,
    // comments too
    b:char
}

fn bar(x:Box<int>) {   // comment here should not affect the next indent
    bla();
    bla();
}"))

(ert-deftest indent-top-level ()
  (test-indent
   "
// Everything here is at the top level and should not be indented
#[attrib]
mod foo;

pub static bar = Quux{a: b()}

use foo::bar::baz;

fn foo() { }
"))

(ert-deftest indent-params-no-align ()
  (test-indent
   "
// Indent out one level because no params appear on the first line
fn xyzzy(
    a:int,
    b:char) { }

fn abcdef(
    a:int,
    b:char)
    -> char
{ }"))

(ert-deftest indent-params-align ()
  (test-indent
   "
// Align the second line of params to the first
fn foo(a:int,
       b:char) { }

fn bar(   a:int,
          b:char)
          -> int
{ }

fn baz(   a:int,  // should work with a comment here
          b:char)
          -> int
{ }
"))

(ert-deftest indent-square-bracket-alignment ()
  (test-indent
   "
fn args_on_the_next_line( // with a comment
    a:int,
    b:String) {
    let aaaaaa = [
        1,
        2,
        3];
    let bbbbbbb = [1, 2, 3,
                   4, 5, 6];
    let ccc = [   10, 9, 8,
                  7, 6, 5];
}
"))

(ert-deftest indent-nested-fns ()
  (test-indent
   "
fn nexted_fns(a: fn(b:int,
                    c:char)
                    -> int,
              d: int)
              -> uint
{
    0
}
"
   ))

(ert-deftest indent-multi-line-expr ()
  (test-indent
   "
fn foo()
{
    x();
    let a =
        b();
}
"
   ))

(ert-deftest indent-match ()
  (test-indent
   "
fn foo() {
    match blah {
        Pattern => stuff(),
        _ => whatever
    }
}
"
   ))

(ert-deftest indent-match-multiline-pattern ()
  (test-indent
   "
fn foo() {
    match blah {
        Pattern |
        Pattern2 => {
            hello()
        },
        _ => whatever
    }
}
"
   ))

(ert-deftest indent-indented-match ()
  (test-indent
   "
fn foo() {
    let x =
        match blah {
            Pattern |
            Pattern2 => {
                hello()
            },
            _ => whatever
        };
    y();
}
"
   ))

(ert-deftest indent-curly-braces-within-parens ()
  (test-indent
   "
fn foo() {
    let x =
        foo(bar(|x| {
            only_one_indent_here();
        }));
    y();
}
"
   ))

(ert-deftest indent-weirdly-indented-block ()
  (rust-test-manip-code
   "
fn foo() {
 {
this_block_is_over_to_the_left_for_some_reason();
 }

}
"
   16
   #'indent-for-tab-command
   "
fn foo() {
 {
     this_block_is_over_to_the_left_for_some_reason();
 }

}
"
   ))

(ert-deftest indent-multi-line-attrib ()
  (test-indent
   "
#[attrib(
    this,
    that,
    theotherthing)]
fn function_with_multiline_attribute() {}
"
   ))


;; Make sure that in effort to cover match patterns we don't mistreat || or expressions
(ert-deftest indent-nonmatch-or-expression ()
  (test-indent
   "
fn foo() {
    let x = foo() ||
        bar();
}
"
   ))

;; Closing braces in single char literals and strings should not confuse the indentation
(ert-deftest indent-closing-braces-in-char-literals ()
  (test-indent
   "
fn foo() {
    { bar('}'); }
    { bar(']'); }
    { bar(')'); }
}
"
   ))

(setq rust-test-motion-string
      "
fn fn1(arg: int) -> bool {
    let x = 5;
    let y = b();
    true
}

fn fn2(arg: int) -> bool {
    let x = 5;
    let y = b();
    true
}

pub fn fn3(arg: int) -> bool {
    let x = 5;
    let y = b();
    true
}

struct Foo {
    x: int
}
"
      rust-test-region-string rust-test-motion-string
      rust-test-indent-motion-string
      "
fn blank_line(arg:int) -> bool {

}

fn indenting_closing_brace() {
    if(true) {
}
}

fn indenting_middle_of_line() {
    if(true) {
 push_me_out();
} else {
               pull_me_back_in();
}
}

fn indented_already() {

    // The previous line already has its spaces
}
"

      ;; Symbol -> (line column)
      rust-test-positions-alist '((start-of-fn1 (2 0))
                                  (start-of-fn1-middle-of-line (2 15))
                                  (middle-of-fn1 (3 7))
                                  (end-of-fn1 (6 0))
                                  (between-fn1-fn2 (7 0))
                                  (start-of-fn2 (8 0))
                                  (middle-of-fn2 (10 4))
                                  (before-start-of-fn1 (1 0))
                                  (after-end-of-fn2 (13 0))
                                  (beginning-of-fn3 (14 0))
                                  (middle-of-fn3 (16 4))
                                  (middle-of-struct (21 10))
                                  (before-start-of-struct (19 0))
                                  (after-end-of-struct (23 0))
                                  (blank-line-indent-start (3 0))
                                  (blank-line-indent-target (3 4))
                                  (closing-brace-indent-start (8 1))
                                  (closing-brace-indent-target (8 5))
                                  (middle-push-indent-start (13 2))
                                  (middle-push-indent-target (13 9))
                                  (after-whitespace-indent-start (13 1))
                                  (after-whitespace-indent-target (13 8))
                                  (middle-pull-indent-start (15 19))
                                  (middle-pull-indent-target (15 12))
                                  (blank-line-indented-already-bol-start (20 0))
                                  (blank-line-indented-already-bol-target (20 4))
                                  (blank-line-indented-already-middle-start (20 2))
                                  (blank-line-indented-already-middle-target (20 4))
                                  (nonblank-line-indented-already-bol-start (21 0))
                                  (nonblank-line-indented-already-bol-target (21 4))
                                  (nonblank-line-indented-already-middle-start (21 2))
                                  (nonblank-line-indented-already-middle-target (21 4))))

(defun rust-get-buffer-pos (pos-symbol)
  "Get buffer position from POS-SYMBOL.

POS-SYMBOL is a symbol found in `rust-test-positions-alist'.
Convert the line-column information from that list into a buffer position value."
  (interactive "P")
  (let* (
         (line-and-column (cadr (assoc pos-symbol rust-test-positions-alist)))
         (line (nth 0 line-and-column))
         (column (nth 1 line-and-column)))
    (save-excursion
      (goto-line line)
      (move-to-column column)
      (point))))

;;; FIXME: Maybe add an ERT explainer function (something that shows the
;;; surrounding code of the final point, not just the position).
(defun rust-test-motion (source-code init-pos final-pos manip-func &optional &rest args)
  "Test that MANIP-FUNC moves point from INIT-POS to FINAL-POS.

If ARGS are provided, send them to MANIP-FUNC.

INIT-POS, FINAL-POS are position symbols found in `rust-test-positions-alist'."
  (with-temp-buffer
    (rust-mode)
    (insert source-code)
    (goto-char (rust-get-buffer-pos init-pos))
    (apply manip-func args)
    (should (equal (point) (rust-get-buffer-pos final-pos)))))

(defun rust-test-region (source-code init-pos reg-beg reg-end manip-func &optional &rest args)
  "Test that MANIP-FUNC marks region from REG-BEG to REG-END.

INIT-POS is the initial position of point.
If ARGS are provided, send them to MANIP-FUNC.
All positions are position symbols found in `rust-test-positions-alist'."
  (with-temp-buffer
    (rust-mode)
    (insert source-code)
    (goto-char (rust-get-buffer-pos init-pos))
    (apply manip-func args)
    (should (equal (list (region-beginning) (region-end))
                   (list (rust-get-buffer-pos reg-beg)
                         (rust-get-buffer-pos reg-end))))))

(ert-deftest rust-beginning-of-defun-from-middle-of-fn ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn1
   'start-of-fn1
   #'beginning-of-defun))

(ert-deftest rust-beginning-of-defun-from-end ()
  (rust-test-motion
   rust-test-motion-string
   'end-of-fn1
   'start-of-fn1
   #'beginning-of-defun))

(ert-deftest rust-beginning-of-defun-before-open-brace ()
  (rust-test-motion
   rust-test-motion-string
   'start-of-fn1-middle-of-line
   'start-of-fn1
   #'beginning-of-defun))

(ert-deftest rust-beginning-of-defun-between-fns ()
  (rust-test-motion
   rust-test-motion-string
   'between-fn1-fn2
   'start-of-fn1
   #'beginning-of-defun))

(ert-deftest rust-beginning-of-defun-with-arg ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn2
   'start-of-fn1
   #'beginning-of-defun 2))

(ert-deftest rust-beginning-of-defun-with-negative-arg ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn1
   'beginning-of-fn3
   #'beginning-of-defun -2))

(ert-deftest rust-beginning-of-defun-pub-fn ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn3
   'beginning-of-fn3
   #'beginning-of-defun))

(ert-deftest rust-end-of-defun-from-middle-of-fn ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn1
   'between-fn1-fn2
   #'end-of-defun))

(ert-deftest rust-end-of-defun-from-beg ()
  (rust-test-motion
   rust-test-motion-string
   'start-of-fn1
   'between-fn1-fn2
   #'end-of-defun))

(ert-deftest rust-end-of-defun-before-open-brace ()
  (rust-test-motion
   rust-test-motion-string
   'start-of-fn1-middle-of-line
   'between-fn1-fn2
   #'end-of-defun))

(ert-deftest rust-end-of-defun-between-fns ()
  (rust-test-motion
   rust-test-motion-string
   'between-fn1-fn2
   'after-end-of-fn2
   #'end-of-defun))

(ert-deftest rust-end-of-defun-with-arg ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn1
   'after-end-of-fn2
   #'end-of-defun 2))

(ert-deftest rust-end-of-defun-with-negative-arg ()
  (rust-test-motion
   rust-test-motion-string
   'middle-of-fn3
   'between-fn1-fn2
   #'end-of-defun -2))

(ert-deftest rust-mark-defun-from-middle-of-fn ()
  (rust-test-region
   rust-test-region-string
   'middle-of-fn2
   'between-fn1-fn2 'after-end-of-fn2
   #'mark-defun))

(ert-deftest rust-mark-defun-from-end ()
  (rust-test-region
   rust-test-region-string
   'end-of-fn1
   'before-start-of-fn1 'between-fn1-fn2
   #'mark-defun))

(ert-deftest rust-mark-defun-start-of-defun ()
  (rust-test-region
   rust-test-region-string
   'start-of-fn2
   'between-fn1-fn2 'after-end-of-fn2
   #'mark-defun))

(ert-deftest rust-mark-defun-from-middle-of-struct ()
  (rust-test-region
   rust-test-region-string
   'middle-of-struct
   'before-start-of-struct 'after-end-of-struct
   #'mark-defun))

(ert-deftest indent-line-blank-line-motion ()
  (rust-test-motion
   rust-test-indent-motion-string
   'blank-line-indent-start
   'blank-line-indent-target
   #'indent-for-tab-command))

(ert-deftest indent-line-closing-brace-motion ()
  (rust-test-motion
   rust-test-indent-motion-string
   'closing-brace-indent-start
   'closing-brace-indent-target
   #'indent-for-tab-command))

(ert-deftest indent-line-middle-push-motion ()
  (rust-test-motion
   rust-test-indent-motion-string
   'middle-push-indent-start
   'middle-push-indent-target
   #'indent-for-tab-command))

(ert-deftest indent-line-after-whitespace-motion ()
  (rust-test-motion
   rust-test-indent-motion-string
   'after-whitespace-indent-start
   'after-whitespace-indent-target
   #'indent-for-tab-command))

(ert-deftest indent-line-middle-pull-motion ()
  (rust-test-motion
   rust-test-indent-motion-string
   'middle-pull-indent-start
   'middle-pull-indent-target
   #'indent-for-tab-command))

(ert-deftest indent-line-blank-line-indented-already-bol ()
  (rust-test-motion
   rust-test-indent-motion-string
   'blank-line-indented-already-bol-start
   'blank-line-indented-already-bol-target
   #'indent-for-tab-command))

(ert-deftest indent-line-blank-line-indented-already-middle ()
  (rust-test-motion
   rust-test-indent-motion-string
   'blank-line-indented-already-middle-start
   'blank-line-indented-already-middle-target
   #'indent-for-tab-command))

(ert-deftest indent-line-nonblank-line-indented-already-bol ()
  (rust-test-motion
   rust-test-indent-motion-string
   'nonblank-line-indented-already-bol-start
   'nonblank-line-indented-already-bol-target
   #'indent-for-tab-command))

(ert-deftest indent-line-nonblank-line-indented-already-middle ()
  (rust-test-motion
   rust-test-indent-motion-string
   'nonblank-line-indented-already-middle-start
   'nonblank-line-indented-already-middle-target
   #'indent-for-tab-command))

(defun rust-test-fontify-string (str)
  (with-temp-buffer
    (rust-mode)
    (insert str)
    (font-lock-fontify-buffer)
    (buffer-string)))

(defun rust-test-group-str-by-face (str)
  "Fontify `STR' in rust-mode and group it by face, returning a
list of substrings of `STR' each followed by its face."
  (loop with fontified = (rust-test-fontify-string str)
        for start = 0 then end
        while start
        for end   = (next-single-property-change start 'face fontified)
        for prop  = (get-text-property start 'face fontified)
        for text  = (substring-no-properties fontified start end)
        if prop
        append (list text prop)))

(defun rust-test-font-lock (source face-groups)
  "Test that `SOURCE' fontifies to the expected `FACE-GROUPS'"
  (should (equal (rust-test-group-str-by-face source)
                 face-groups)))

(ert-deftest font-lock-attribute-simple ()
  (rust-test-font-lock
   "#[foo]"
   '("#[foo]" font-lock-preprocessor-face)))

(ert-deftest font-lock-attribute-inner ()
  (rust-test-font-lock
   "#![foo]"
   '("#![foo]" font-lock-preprocessor-face)))

(ert-deftest font-lock-attribute-key-value ()
  (rust-test-font-lock
   "#[foo = \"bar\"]"
   '("#[foo = " font-lock-preprocessor-face
     "\"bar\"" font-lock-string-face
     "]" font-lock-preprocessor-face)))

(ert-deftest font-lock-attribute-around-comment ()
  (rust-test-font-lock
   "#[foo /* bar */]"
   '("#[foo " font-lock-preprocessor-face
     "/* " font-lock-comment-delimiter-face
     "bar */" font-lock-comment-face
     "]" font-lock-preprocessor-face)))

(ert-deftest font-lock-attribute-inside-string ()
  (rust-test-font-lock
   "\"#[foo]\""
   '("\"#[foo]\"" font-lock-string-face)))

(ert-deftest font-lock-attribute-inside-comment ()
  (rust-test-font-lock
   "/* #[foo] */"
   '("/* " font-lock-comment-delimiter-face
     "#[foo] */" font-lock-comment-face)))

(ert-deftest font-lock-double-quote-character-literal ()
  (rust-test-font-lock
   "'\"'; let"
   '("'\"'" font-lock-string-face
     "let" font-lock-keyword-face)))

(ert-deftest font-lock-single-quote-character-literal ()
  (rust-test-font-lock
   "fn main() { let ch = '\\''; }"
   '("fn" font-lock-keyword-face
     "main" font-lock-function-name-face
     "let" font-lock-keyword-face
     "'\\''" font-lock-string-face)))

(ert-deftest font-lock-raw-strings-no-hashes ()
  (rust-test-font-lock
   "r\"No hashes\";"
   '("r\"No hashes\"" font-lock-string-face)))

(ert-deftest font-lock-raw-strings-double-quote ()
  (rust-test-font-lock
   "fn main() {
    r#\"With a double quote (\")\"#;
}
"
   '("fn" font-lock-keyword-face
     "main" font-lock-function-name-face
     "r#\"With a double quote (\")\"#" font-lock-string-face)))

(ert-deftest font-lock-raw-strings-two-hashes ()
  (rust-test-font-lock
   "r##\"With two hashes\"##;"
   '("r##\"With two hashes\"##" font-lock-string-face)))

(ert-deftest font-lock-raw-strings-backslash-at-end ()
  (rust-test-font-lock
   "r\"With a backslash at the end\\\";"
   '("r\"With a backslash at the end\\\"" font-lock-string-face)))

(ert-deftest font-lock-two-raw-strings ()
  (rust-test-font-lock
   "fn main() {
    r\"With a backslash at the end\\\";
    r##\"With two hashes\"##;
}"
   '("fn" font-lock-keyword-face
     "main" font-lock-function-name-face
     "r\"With a backslash at the end\\\"" font-lock-string-face
     "r##\"With two hashes\"##" font-lock-string-face)))

(ert-deftest font-lock-raw-string-with-inner-hash ()
  (rust-test-font-lock
   "r##\"I've got an octothorpe (#)\"##; foo()"
   '("r##\"I've got an octothorpe (#)\"##" font-lock-string-face)))

(ert-deftest font-lock-raw-string-with-inner-quote-and-hash ()
  (rust-test-font-lock
   "not_the_string(); r##\"string \"# still same string\"##; not_the_string()"
   '("r##\"string \"# still same string\"##" font-lock-string-face)))

(ert-deftest font-lock-string-ending-with-r-not-raw-string ()
  (rust-test-font-lock
   "fn f() {
    \"Er\";
}

fn g() {
    \"xs\";
}"
   '("fn" font-lock-keyword-face
     "f" font-lock-function-name-face
     "\"Er\"" font-lock-string-face
     "fn" font-lock-keyword-face
     "g" font-lock-function-name-face
     "\"xs\"" font-lock-string-face)))

(ert-deftest font-lock-raw-string-trick-ending-followed-by-string-with-quote ()
  (rust-test-font-lock
   "r\"With what looks like the start of a raw string at the end r#\";
not_a_string();
r##\"With \"embedded\" quote \"##;"
   '("r\"With what looks like the start of a raw string at the end r#\"" font-lock-string-face
     "r##\"With \"embedded\" quote \"##" font-lock-string-face)))

(ert-deftest font-lock-raw-string-starter-inside-raw-string ()
  ;; Check that it won't look for a raw string beginning inside another raw string.
  (rust-test-font-lock
   "r#\"In the first string r\" in the first string \"#;
not_in_a_string();
r##\"In the second string\"##;"
   '("r#\"In the first string r\" in the first string \"#" font-lock-string-face
     "r##\"In the second string\"##" font-lock-string-face)))

(ert-deftest font-lock-raw-string-starter-inside-comment ()
  ;; Check that it won't look for a raw string beginning inside another raw string.
  (rust-test-font-lock
   "// r\" this is a comment
\"this is a string\";
this_is_not_a_string();)"
   '("// " font-lock-comment-delimiter-face
     "r\" this is a comment\n" font-lock-comment-face
     "\"this is a string\"" font-lock-string-face)))

(ert-deftest indent-method-chains-no-align ()
  (let ((rust-indent-method-chain nil)) (test-indent
   "
fn main() {
    let x = thing.do_it()
        .aligned()
        .more_alignment();
}
"
   )))

(ert-deftest indent-method-chains-with-align ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    let x = thing.do_it()
                 .aligned()
                 .more_alignment();
}
"
   )))

(ert-deftest indent-method-chains-with-align-and-second-stmt ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    let x = thing.do_it()
                 .aligned()
                 .more_alignment();
    foo.bar();
}
"
   )))

(ert-deftest indent-method-chains-field ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    let x = thing.do_it
                 .aligned
                 .more_alignment();
}
"
   )))

(ert-deftest indent-method-chains-double-field-on-first-line ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    let x = thing.a.do_it
                   .aligned
                   .more_alignment();
}
"
   )))

(ert-deftest indent-method-chains-no-let ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    thing.a.do_it
           .aligned
           .more_alignment();
}
"
   )))

(ert-deftest indent-method-chains-comment ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    // thing.do_it()
    // .aligned()
}
"
   )))

(ert-deftest indent-method-chains-close-block ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() {
    foo.bar()
}
"
   )))

(ert-deftest indent-method-chains-after-comment ()
  (let ((rust-indent-method-chain t)) (test-indent
   "
fn main() { // comment here should not push next line out
    foo.bar()
}
"
   )))

(ert-deftest test-for-issue-36-syntax-corrupted-state ()
  "This is a test for a issue #36, which involved emacs's
internal state getting corrupted when actions were done in a
specific sequence.  The test seems arbitrary, and is, but it was
not clear how to narrow it down further.

The cause of the bug was code that used to set
`syntax-begin-function' to `beginning-of-defun', which doesn't
actually fulfill the expectations--`syntax-begin-function' is
supposed to back out of all parens, but `beginning-of-defun'
could leave it inside parens if a fn appears inside them.

Having said that, as I write this I don't understand fully what
internal state was corrupted and how.  There wasn't an obvious
pattern to what did and did not trip it."
  
  ;; When bug #36 was present, the following test would pass, but running it
  ;; caused some unknown emacs state to be corrupted such that the following
  ;; test failed.  Both the "blank_line" and "indented_closing_brace" functions
  ;; were needed to expose the error, for instance--deleting either of them
  ;; would make the failure go away.
  (with-temp-buffer
    (rust-mode)
    (insert "fn blank_line(arg:int) -> bool {

}

fn indenting_closing_brace() {
    if(true) {
}
}

fn indented_already() {
    \n    // The previous line already has its spaces
}
")

    (goto-line 11)
    (move-to-column 0)
    (indent-for-tab-command)
    (should (equal (current-column) 4))
    )

  ;; This is the test that would fail only after running the previous one.  The
  ;; code is extracted from src/libstd/collections/table.rs in the rust tree.
  ;; It was not clear how to reduce it further--removing various bits of it
  ;; would make it no longer fail.  In particular, changing only the comment at
  ;; the top of the "next" function was sufficient to make it no longer fail.
  (test-indent
   "
impl Foo for Bar {
    
    /// Modifies the bucket pointer in place to make it point to the next slot.
    pub fn next(&mut self) {
        // Branchless bucket
        // As we reach the end of the table...
        // We take the current idx:          0111111b
        // Xor it by its increment:        ^ 1000000b
        //                               ------------
        //                                   1111111b
        // Then AND with the capacity:     & 1000000b
        //                               ------------
        // to get the backwards offset:      1000000b
        let maybe_wraparound_dist = (self.idx ^ (self.idx + 1)) & self.table.capacity();
        // Finally, we obtain the offset 1 or the offset -cap + 1.
        let dist = 1 - (maybe_wraparound_dist as isize);
        
        self.idx += 1;
        
        unsafe {
            self.raw = self.raw.offset(dist);
        }
    }
    
    /// Reads a bucket at a given index, returning an enum indicating whether
    /// the appropriate types to call most of the other functions in
    /// this module.
    pub fn peek(self) {
        match foo {
            EMPTY_BUCKET =>
                Empty(EmptyBucket {
                    raw: self.raw,
                    idx: self.idx,
                    table: self.table
                }),
            _ =>
                Full(FullBucket {
                    raw: self.raw,
                    idx: self.idx,
                    table: self.table
                })
        }
    }    
}
"
   ))