Support for macOS, mainly by replacing inotify with watchgod, which works cross-plattform

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "native/inotify_simple"]
-	path = native/inotify_simple
-	url = https://github.com/chrisjbillington/inotify_simple
+[submodule "native/watchgod"]
+	path = native/watchgod
+	url = https://github.com/samuelcolvin/watchgod

Makefile

@@ -1,10 +1,20 @@
+UNAME_S := $(shell uname -s)
+
 ifneq ($(USER),1)
 	PREFIX ?= /usr/local
-	MOZILLA_PREFIX ?= /usr
-	MOZILLA_NATIVE ?= $(MOZILLA_PREFIX)/lib64/mozilla/native-messaging-hosts
+	ifeq ($(UNAME_S),Darwin)
+		MOZILLA_NATIVE ?= /Library/Application\ Support/Mozilla/NativeMessagingHosts
+	else
+		MOZILLA_PREFIX ?= /usr
+		MOZILLA_NATIVE ?= $(MOZILLA_PREFIX)/lib64/mozilla/native-messaging-hosts
+	endif
 else
 	PREFIX ?= $(HOME)/.local
-	MOZILLA_NATIVE ?= $(HOME)/.mozilla/native-messaging-hosts
+	ifeq ($(UNAME_S),Darwin)
+		MOZILLA_NATIVE ?= $(HOME)/Library/Application\ Support/Mozilla/NativeMessagingHosts
+	else
+		MOZILLA_NATIVE ?= $(HOME)/.mozilla/native-messaging-hosts
+	endif
 endif
 
 LIBEXEC ?= $(PREFIX)/libexec
@@ -28,7 +38,7 @@ native-install: native/textern.json
 	mkdir -p $(DESTDIR)$(MOZILLA_NATIVE)
 	cp -f native/textern.json $(DESTDIR)$(MOZILLA_NATIVE)
 	mkdir -p $(DESTDIR)$(LIBEXEC)/textern
-	cp -rf native/textern.py native/inotify_simple $(DESTDIR)$(LIBEXEC)/textern
+	cp -rf native/textern.py native/watchgod $(DESTDIR)$(LIBEXEC)/textern
 
 .PHONY: native-uninstall
 native-uninstall:

README.md

@@ -16,7 +16,7 @@ The add-on is divided into two parts:
 - the native application, which handles text editor
   launching and monitoring.
 
-The native application currently only supports Linux with
+The native application currently supports Linux or macOS with
 Python 3.5. Patches to add support for other platforms are
 welcome!
 
@@ -53,6 +53,18 @@ the native app for the current user, run:
 $ make native-install USER=1
 ```
 
+
+### Note for macOS
+
+If you installed Python via [homebrew](https://brew.sh/), note
+that `/usr/local/bin` is *not* on the PATH by default, so
+`textern.py` cannot find it. You either need to adjust your
+PATH globally, the exact procedure for which seems to [change with
+each macOS version](https://stackoverflow.com/a/32902449/1885340),
+or edit the first line of `native/textern.py` to read
+`#!/usr/local/bin/python3` and repeating the `make native-install` call.
+
+
 ## Usage
 
 Once both the WebExtension and the native application are
@@ -118,6 +130,14 @@ set your editor in the preferences to something like
 and make sure, that `gnome-terminal-wrapper` is in your
 `PATH`.
 
+### Notes on the macOS Terminal.app
+
+As it operates similarly to gnome-terminal (described above),
+it has the same issue with exiting prematurely. An appropriate
+wrapper script can be found
+[here](https://gist.github.com/wosc/680f87845d0fd9d8b4a9e2f8c42f98a2)
+
+
 ### GUI editors
 
 Non-terminal-based editors can also suffer from the same

native/textern.py

@@ -12,14 +12,19 @@
 import asyncio
 import tempfile
 import urllib.parse
-from inotify_simple.inotify_simple import INotify, flags
+from watchgod.watchgod import awatch
+
+if sys.platform == 'darwin':
+    TMPDIR = os.environ['TMPDIR']
+else:
+    TMPDIR = os.environ['XDG_RUNTIME_DIR']
 
 
 class TmpManager():
 
     def __init__(self):
         try:
-            tmpdir_parent = os.path.join(os.environ['XDG_RUNTIME_DIR'], 'textern')
+            tmpdir_parent = os.path.join(TMPDIR, 'textern')
             os.makedirs(tmpdir_parent)
         except:
             tmpdir_parent = None
@@ -63,11 +68,10 @@ def has(self, relfn):
 
 
 def main():
-    with INotify() as ino, TmpManager() as tmp_mgr:
-        ino.add_watch(tmp_mgr.tmpdir, flags.CLOSE_WRITE)
+    with TmpManager() as tmp_mgr:
         loop = asyncio.get_event_loop()
+        loop.create_task(watch_directory(tmp_mgr))
         loop.add_reader(sys.stdin.buffer, handle_stdin, tmp_mgr)
-        loop.add_reader(ino.fd, handle_inotify_event, ino, tmp_mgr)
         loop.run_forever()
         loop.close()
 
@@ -161,14 +165,16 @@ async def handle_message_new_text(tmp_mgr, msg):
 }
 
 
-def handle_inotify_event(ino, tmp_mgr):
-    for event in ino.read():
-        # this check is relevant in the case where we're handling the inotify
-        # event caused by tmp_mgr.new(), but then an exception occurred in
-        # handle_message() which caused the tmpfile to already be deleted
-        if tmp_mgr.has(event.name):
-            text, id = tmp_mgr.get(event.name)
-            send_text_update(id, text)
+async def watch_directory(tmp_mgr):
+    async for changes in awatch(tmp_mgr.tmpdir):
+        for typ, path in changes:
+            path = os.path.basename(path)
+            # this check is relevant in the case where we're handling the
+            # event caused by tmp_mgr.new(), but then an exception occurred in
+            # handle_message() which caused the tmpfile to already be deleted
+            if tmp_mgr.has(path):
+                text, id = tmp_mgr.get(path)
+                send_text_update(id, text)
 
 
 def send_text_update(id, text):