Rename variable prefix and add tests for regexp

4 files changed, 67 insertions, 12 deletions

diff --git a/Makefile b/Makefile
index 3acc1df..8045ed2 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,7 @@
-.PHONY: build clean
+.PHONY: build test clean
+
+test: build
+	emacs -batch -l ert -L . -l clippy-flymake-test.el -f ert-run-tests-batch-and-exit
 
 build: clean
 	emacs -batch -L . -f batch-byte-compile clippy-flymake.el
diff --git a/clippy-flymake-test.el b/clippy-flymake-test.el
new file mode 100644
index 0000000..f33db6c
--- /dev/null
+++ b/clippy-flymake-test.el
@@ -0,0 +1,31 @@
+;;; clippy-flymake-test.el   -*- lexical-binding: t; -*-
+
+(require 'clippy-flymake)
+(require 'ert)
+
+(defun run-regexp (filename)
+  (set-match-data nil)
+  (search-forward-regexp (clippy-flymake--build-regexp filename) nil t)
+  (list (match-string 1)
+        (match-string 2)
+        (match-string 3)))
+
+(ert-deftest clippy-test-regexp ()
+  "Tests regexp matches diagnostic information."
+  (should (equal (with-temp-buffer
+                   (insert-file-contents "./test/fixture.txt")
+                   (run-regexp "foo.rs"))
+                 '("warning: unused variable: `user`" "  --> src/database/foo.rs" "42")))
+  (should (equal (with-temp-buffer
+                   (insert-file-contents "./test/fixture.txt")
+                   (run-regexp "foo.rs")
+                   (run-regexp "foo.rs"))
+                 '("warning: using `clone` on type `Status` which implements the `Copy` trait" "  --> src/foo.rs" "31")))
+  (should (equal (with-temp-buffer
+                   (insert-file-contents "./test/fixture.txt")
+                   (run-regexp "user.rs"))
+                 '("warning: unused variable: `user`" "  --> src/foobar/user.rs" "42")))
+  (should (equal (with-temp-buffer
+                   (insert-file-contents "./test/fixture.txt")
+                   (run-regexp "notfound.rs"))
+                 '(nil nil nil))))
diff --git a/clippy-flymake.el b/clippy-flymake.el
index 42bc56a..b61abd4 100644
--- a/clippy-flymake.el
+++ b/clippy-flymake.el
@@ -31,7 +31,7 @@
 ;; "warning: ..."
 ;;    --> src/filename.rs
 ;; 98 | ...
-(defun clippy--build-regexp (filename)
+(defun clippy-flymake--build-regexp (filename)
   "Create a regular expression to search Clippy warnings for FILENAME."
   (rx-to-string
    `(seq line-start
@@ -55,10 +55,10 @@
            (any "0-9")))
          line-end)))
 
-(defvar clippy--flymake-proc nil
+(defvar clippy-flymake--proc nil
   "Clippy subprocess object, used to ensure obsolete processes aren't reused.")
 
-(defun clippy-flymake (report-fn &rest _args)
+(defun clippy-flymake--check-buffer (report-fn &rest _args)
   "Flymake backend for cargo clippy. REPORT-FN is passed in via
 `flymake-diagnostic-functions' hook.
 
@@ -71,7 +71,7 @@ with the appropriate Flymake hook."
          (filename (file-name-nondirectory (buffer-file-name source))))
     (save-restriction
       (widen)
-      (setq clippy--flymake-proc
+      (setq clippy-flymake--proc
             (make-process
              :name "clippy-flymake" :noquery t :connection-type 'pipe
              :buffer (generate-new-buffer "*clippy-flymake*")
@@ -80,14 +80,14 @@ with the appropriate Flymake hook."
              (lambda (proc _event)
                (when (memq (process-status proc) '(exit signal))
                  (unwind-protect
-                     (if (with-current-buffer source (eq proc clippy--flymake-proc))
+                     (if (with-current-buffer source (eq proc clippy-flymake--proc))
                          (with-current-buffer (process-buffer proc)
                            (goto-char (point-min))
                            ;; Collect output buffer into diagnostic messages/locations,
                            ;; exposing them via `report-fn'.
                            (cl-loop
                             while (search-forward-regexp
-                                   (clippy--build-regexp filename)
+                                   (clippy-flymake--build-regexp filename)
                                    nil t)
                             for msg = (match-string 1)
                             for (beg . end) = (flymake-diag-region
@@ -102,12 +102,12 @@ with the appropriate Flymake hook."
                        (flymake-log :warning "Canceling obsolete check %s" proc))
                    ;; Cleanup temp buffer.
                    (kill-buffer (process-buffer proc)))))))
-      (process-send-region clippy--flymake-proc (point-min) (point-max))
-      (process-send-eof clippy--flymake-proc))))
+      (process-send-region clippy-flymake--proc (point-min) (point-max))
+      (process-send-eof clippy-flymake--proc))))
 
 (defun clippy-flymake-setup-backend ()
   "Add `clippy-flymake' to `flymake-diagnostic-functions' hook."
-  (add-hook 'flymake-diagnostic-functions #'clippy-flymake nil t))
+  (add-hook 'flymake-diagnostic-functions #'clippy-flymake--check-buffer nil t))
 
-(provide 'flymake-clippy)
-;;; flymake-clippy.el ends here
+(provide 'clippy-flymake)
+;;; clippy-flymake.el ends here
diff --git a/test/fixture.txt b/test/fixture.txt
new file mode 100644
index 0000000..9bbcbea
--- /dev/null
+++ b/test/fixture.txt
@@ -0,0 +1,21 @@
+warning: unused variable: `user`
+  --> src/database/foo.rs:42:9
+   |
+42 |         user: &User,
+   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_user`
+   |
+   = note: `#[warn(unused_variables)]` on by default
+
+warning: using `clone` on type `Status` which implements the `Copy` trait
+  --> src/foo.rs:31:29
+   |
+31 |             Some(status) => status.clone(),
+   |                             ^^^^^^^^^^^^^^ help: try dereferencing it: `*status`
+
+warning: unused variable: `user`
+  --> src/foobar/user.rs:42:9
+   |
+42 |         user: &User,
+   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_user`
+   |
+   = note: `#[warn(unused_variables)]` on by default