Test PureScript indentation

Makefile

@@ -25,6 +25,7 @@ ELFILES = \
 	purescript-decl-scan.el \
 	purescript-yas.el \
 	tests/purescript-sort-imports-tests.el \
+	tests/purescript-indentation-tests.el \
 	tests/purescript-str-tests.el
 
 ELCFILES = $(ELFILES:.el=.elc)
@@ -46,6 +47,7 @@ compile: $(ELCFILES)
 test: compile
 	@$(BATCH) -l tests/purescript-sort-imports-tests.elc \
 		-l tests/purescript-str-tests.elc \
+		-l tests/purescript-indentation-tests.elc \
 		-f ert-run-tests-batch-and-exit
 	@echo "tests passed!"
 

purescript-indentation.el

@@ -111,13 +111,6 @@
   :group 'purescript-indentation)
 
 
-;; Avoid a global bogus definition (which the original run-time
-;; `defun' made), and support Emacs 21 without the syntax.el add-on.
-(eval-when-compile
-  (unless (fboundp 'syntax-ppss)
-    (defsubst syntax-ppss (&rest pos)
-      (parse-partial-sexp (point-min) (or pos (point))))))
-
 (defconst purescript-indentation-mode-map
   (let ((keymap (make-sparse-keymap)))
     (define-key keymap [?\r] 'purescript-newline-and-indent)

tests/purescript-indentation-tests.el

@@ -0,0 +1,240 @@
+;;; purescript-indentation-tests.el --- Unit tests for purescript indentation -*- lexical-binding: t -*-
+
+;; Copyright (c) 2025 Konstantin Kharlamov. All rights reserved.
+
+;; This file is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+
+;; This file is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'purescript-mode)
+(require 'purescript-indentation)
+
+(defun purescript-test-indentation (before after &optional start-line)
+  (with-temp-buffer
+    (insert before)
+    (purescript-mode)
+    (turn-on-purescript-indentation)
+    (indent-region (if start-line start-line (point-min))
+                   (point-max))
+    (should (string= after (buffer-string)))))
+
+(ert-deftest newtype-comma-first ()
+  (purescript-test-indentation "
+newtype Foo = Foo { field1 :: MyType
+, field2 :: Int
+, field3 :: HashMap ParType Foo }"
+
+"
+newtype Foo = Foo { field1 :: MyType
+                  , field2 :: Int
+                  , field3 :: HashMap ParType Foo }"))
+
+(ert-deftest newtype-comma-end ()
+  (purescript-test-indentation "
+newtype Foo = Foo { field1 :: MyType,
+field2 :: Int,
+field3 :: HashMap ParType Foo }"
+
+"
+newtype Foo = Foo { field1 :: MyType,
+                    field2 :: Int,
+                    field3 :: HashMap ParType Foo }"))
+
+(ert-deftest data-bar-first ()
+  (purescript-test-indentation "
+data Foo = Foo1 Bar
+| Foo2 Bar2
+| Foo3 Unit"
+
+"
+data Foo = Foo1 Bar
+         | Foo2 Bar2
+         | Foo3 Unit"))
+
+(ert-deftest data-bar-end ()
+  (purescript-test-indentation "
+data Foo = Foo1 Bar |
+Foo2 Bar2 |
+Foo3 Unit"
+
+"
+data Foo = Foo1 Bar |
+           Foo2 Bar2 |
+           Foo3 Unit"))
+
+(ert-deftest imports-zero-indented ()
+  :expected-result :failed
+  (purescript-test-indentation "
+module MyModule where
+
+import Prelude
+
+    import Data.Array (many)
+    import Data.Array as Array
+    import Data.Either (Either(..))"
+
+"
+module MyModule where
+
+import Prelude
+
+import Data.Array (many)
+import Data.Array as Array
+import Data.Either (Either(..))"))
+
+(ert-deftest imports-indented-forward ()
+  "PureScript allows for imports to have indentation, but the
+ indentation must be the same. In this test we skip first indented
+ import, and test that further lines inherit indentation level."
+  :expected-result :failed
+  (purescript-test-indentation "
+module MyModule where
+
+    import Prelude
+
+import Data.Array (many)
+import Data.Array as Array
+import Data.Either (Either(..))"
+
+"
+module MyModule where
+
+    import Prelude
+
+    import Data.Array (many)
+    import Data.Array as Array
+    import Data.Either (Either(..))"
+    6))
+
+(ert-deftest imports-qualified-newline-comma-first ()
+  :expected-result :failed
+  (purescript-test-indentation "
+import Data.List.NonEmpty (NonEmptyList)
+import Data.Maybe (Maybe(..)
+, fromMaybe)"
+
+"
+import Data.List.NonEmpty (NonEmptyList)
+import Data.Maybe ( Maybe(..)
+                  , fromMaybe)"))
+
+(ert-deftest imports-qualified-newline-comma-end ()
+  :expected-result :failed
+  (purescript-test-indentation "
+import Data.List.NonEmpty (NonEmptyList)
+import Data.Maybe (Maybe(..),
+fromMaybe)"
+
+"
+import Data.List.NonEmpty (NonEmptyList)
+import Data.Maybe (Maybe(..),
+                   fromMaybe)"))
+
+(ert-deftest do-impl ()
+  (purescript-test-indentation "
+main = do
+pure unit"
+
+"
+main = do
+  pure unit"))
+
+(ert-deftest let-bindings ()
+  :expected-result :failed
+  (purescript-test-indentation "
+main = do
+  let foo = 1
+        bar = 2
+  let
+            buzz = 1
+            fuzz = 2
+pure unit"
+
+"
+main = do
+  let foo = 1
+      bar = 2
+  let
+    buzz = 1
+    fuzz = 2
+  pure unit"))
+
+(ert-deftest module-exports-list ()
+  :expected-result :failed
+  (purescript-test-indentation "
+module MyModule ( class A
+, b, c
+, d) where"
+
+"
+module MyModule ( class A
+                , b, c
+                , d) where"))
+
+(ert-deftest module-exports-next-line ()
+  "Parentheses should get indented to the mode indentation size"
+  :expected-result :failed
+  (purescript-test-indentation "
+module MyModule
+            (class A, b, c, d) where"
+
+"
+module MyModule
+  (class A, b, c, d) where"))
+
+(ert-deftest keyword-record-values ()
+  "PureScript allows keywords to be part of a Record declaration"
+  :expected-result :failed
+  (purescript-test-indentation "
+type MyRec = { data :: Number
+, where :: Number
+, instance :: Number
+}"
+
+"
+type MyRec = { data :: Number
+             , where :: Number
+             , instance :: Number
+             }"))
+
+(ert-deftest func-with-do ()
+  :expected-result :failed
+  (purescript-test-indentation "
+foo :: Foo
+foo = do
+  pure unit"
+
+"
+foo :: Foo
+foo = do
+  pure unit"))
+
+(ert-deftest do-bindings ()
+  :expected-result :failed
+  (purescript-test-indentation "
+foo :: Foo
+foo = do
+_ <- something
+identifier :: Array String <- function call
+_ <- another call
+pure unit"
+
+"
+foo :: Foo
+foo = do
+  _ <- something
+  identifier :: Array String <- function call
+  _ <- another call
+  pure unit"))