Add ERT tests

src/etc/emacs/README.md

@@ -68,6 +68,12 @@ marking, press x, and ELPA will install the packages for you (under
 
 * or using <kbd>M-x package-install rust-mode
 
+### Tests via ERT
+
+The file `rust-mode-tests.el` contains tests that can be run via ERT.  You can
+use `run_rust_emacs_tests.sh` to run them in batch mode, if emacs is somewhere
+in your `$PATH`.
+
 ### Known bugs
 
 * Combining `global-whitespace-mode` and `rust-mode` is generally glitchy.

src/etc/emacs/run_rust_emacs_tests.sh

@@ -0,0 +1,3 @@
+# This runs the test for emacs rust-mode.
+# It must be possible to find emacs via PATH.
+emacs -batch -l rust-mode.el -l rust-mode-tests.el -f ert-run-tests-batch-and-exit

src/etc/emacs/rust-mode-tests.el

@@ -0,0 +1,380 @@
+;;; 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
+     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)
+     for pos from (if (= 1 start-pos) 1 (+ padding-adjust start-pos)) to (+ end-pos padding-adjust)
+     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
+ */"))
+
+(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
+   "/**
+ * 
+ */"
+   8
+   "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 () (indent-region 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:~str}"))
+
+(ert-deftest indent-doc-comments ()
+  (test-indent
+"
+/**
+ * This is a doc comment
+ *
+ */
+
+/// So is this
+
+fn foo() {
+    /*!
+     * this is a nested doc comment
+     */
+    
+    //! 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:~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,  // shoudl 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:~str) {
+    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
+}
+"
+))