json-rpc-test-server: add a "wait" method

Considering the server's nature, the global lock-up it causes
shouldn't constitute a major problem.

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 - 2020, Přemysl Eric Janouch <p@janouch.name>
+Copyright (c) 2014 - 2022, Přemysl Eric Janouch <p@janouch.name>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted.

NEWS

@@ -1,3 +1,20 @@
+Unreleased
+
+ * Add a backend for co-processes, such as language servers
+
+ * Support reading OpenRPC documents from a file
+
+ * Respect the NO_COLOR environment variable
+
+ * Miscellaneous libedit (editline) fixes
+
+ * json-rpc-test-server: implement OpenRPC discovery
+
+ * json-rpc-test-server: only serve regular files
+
+ * json-rpc-test-server: miscellaneous WebSocket fixes
+
+
 1.1.0 (2020-10-13)
 
  * Add method name tab completion using OpenRPC information

json-rpc-shell.adoc

@@ -140,8 +140,7 @@ the higher-level protocol (the "Sec-Ws-Protocol" HTTP field).
 
 Bugs
 ----
-The editline (libedit) frontend is more of a proof of concept that mostly seems
-to work but exhibits bugs that are not our fault.
+The editline (libedit) frontend may exhibit some unexpected behaviour.
 
 Examples
 --------

json-rpc-shell.c

@@ -1,7 +1,7 @@
 /*
  * json-rpc-shell.c: a shell for JSON-RPC 2.0
  *
- * Copyright (c) 2014 - 2020, Přemysl Eric Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2022, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -515,6 +515,7 @@ struct input_el
 	char *entered_line;                 ///< Buffers the entered line
 
 	bool active;                        ///< Interface has been started
+	bool need_restart;                  ///< Need to clear history state
 	char *prompt;                       ///< The prompt we use
 	int prompt_shown;                   ///< Whether the prompt is shown now
 
@@ -540,12 +541,24 @@ input_el_redisplay (struct input_el *self)
 {
 	// See rl_redisplay(), however NetBSD editline's map.c v1.54 breaks VREPRINT
 	// so we bind redisplay somewhere else in input_el_start()
-	char x[] = { 'q' & 31, 0 };
-	el_push (self->editline, x);
+	wchar_t x[] = { L'q' & 31, 0 };
+	el_wpush (self->editline, x);
 
 	// We have to do this or it gets stuck and nothing is done
-	int count = 0;
-	(void) el_wgets (self->editline, &count);
+	int dummy_count = 0;
+	(void) el_wgets (self->editline, &dummy_count);
+}
+
+// Editline keeping its own history position (look for "eventno" there).
+// This is the only sane way of resetting it.
+static void
+input_el_start_over (struct input_el *self)
+{
+	wchar_t x[] = { L'c' & 31, 0 };
+	el_wpush (self->editline, x);
+
+	int dummy_count = 0;
+	(void) el_wgets (self->editline, &dummy_count);
 }
 
 static char *
@@ -603,13 +616,14 @@ input_el_on_return (EditLine *editline, int key)
 	self->entered_line = xstrndup
 		(info_mb->buffer, info_mb->lastchar - info_mb->buffer);
 
-	// Now we need to force editline to actually print the newline
+	// Now we need to force editline into actually printing the newline
 	el_cursor (editline, len++ - point);
 	el_insertstr (editline, "\n");
 	input_el_redisplay (self);
 
 	// Finally we need to discard the old line's contents
 	el_wdeletestr (editline, len);
+	self->need_restart = true;
 	return CC_NEWLINE;
 }
 
@@ -673,8 +687,6 @@ input_el_start (struct input *input, const char *program_name)
 	el_set (self->editline, EL_BIND, "^w", "ed-delete-prev-word", NULL);
 	// Just what are you doing?
 	el_set (self->editline, EL_BIND, "^u", "vi-kill-line-prev",   NULL);
-	// See input_el_redisplay(), functionally important
-	el_set (self->editline, EL_BIND, "^q", "ed-redisplay",        NULL);
 
 	// It's probably better to handle these ourselves
 	input_el_addbind (self->editline, "send-line", "Send line",
@@ -690,6 +702,11 @@ input_el_start (struct input *input, const char *program_name)
 	// Source the user's defaults file
 	el_source (self->editline, NULL);
 
+	// See input_el_redisplay(), functionally important
+	el_set (self->editline, EL_BIND, "^q", "ed-redisplay",        NULL);
+	// This is what buffered el_wgets() does, functionally important
+	el_set (self->editline, EL_BIND, "^c", "ed-start-over",       NULL);
+
 	self->active = true;
 	self->prompt_shown = 1;
 }
@@ -977,6 +994,16 @@ input_el_on_tty_readable (struct input *input)
 	// We bind the return key to process it how we need to
 	struct input_el *self = (struct input_el *) input;
 
+	int unbuffered = 0;
+	(void) el_get (self->editline, EL_UNBUFFERED, &unbuffered);
+
+	// We must invoke ch_reset(), which isn't done for us with EL_UNBUFFERED.
+	if (unbuffered && self->need_restart)
+	{
+		self->need_restart = false;
+		input_el_start_over (self);
+	}
+
 	// el_gets() with EL_UNBUFFERED doesn't work with UTF-8,
 	// we must use the wide-character interface
 	int count = 0;
@@ -984,8 +1011,7 @@ input_el_on_tty_readable (struct input *input)
 
 	// Editline works in a funny NO_TTY mode when the input is not a tty,
 	// we cannot use EL_UNBUFFERED and expect sane results then
-	int unbuffered = 0;
-	if (!el_get (self->editline, EL_UNBUFFERED, &unbuffered) && !unbuffered)
+	if (!unbuffered)
 	{
 		char *entered_line = buf ? input_el_wcstombs (buf) : NULL;
 		self->super.on_input (entered_line, self->super.user_data);

json-rpc-test-server.c

@@ -1,7 +1,7 @@
 /*
  * json-rpc-test-server.c: JSON-RPC 2.0 demo server
  *
- * Copyright (c) 2015 - 2020, Přemysl Eric Janouch <p@janouch.name>
+ * Copyright (c) 2015 - 2022, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -1464,7 +1464,7 @@ json_rpc_discover (struct server_context *ctx, json_t *params)
 
 	json_t *info = json_pack ("{ssss}",
 		"title", PROGRAM_NAME, "version", PROGRAM_VERSION);
-	json_t *methods = json_pack ("[ooo]",
+	json_t *methods = json_pack ("[oooo]",
 		open_rpc_describe ("date", json_pack ("{ssso}", "type", "object",
 			"properties", json_pack ("{s{ss}s{ss}s{ss}s{ss}s{ss}s{ss}}",
 				"year",    "type", "number",
@@ -1475,7 +1475,8 @@ json_rpc_discover (struct server_context *ctx, json_t *params)
 				"seconds", "type", "number"))),
 		open_rpc_describe ("ping", json_pack ("{ss}", "type", "string")),
 		open_rpc_describe ("rpc.discover", json_pack ("{ss}", "$ref",
-			"https://github.com/open-rpc/meta-schema/raw/master/schema.json")));
+			"https://github.com/open-rpc/meta-schema/raw/master/schema.json")),
+		open_rpc_describe ("wait", json_pack ("{ss}", "type", "null")));
 	return json_rpc_response (NULL, json_pack ("{sssoso}",
 		"openrpc", "1.2.6", "info", info, "methods", methods), NULL);
 }
@@ -1492,6 +1493,16 @@ json_rpc_ping (struct server_context *ctx, json_t *params)
 	return json_rpc_response (NULL, json_string ("pong"), NULL);
 }
 
+static json_t *
+json_rpc_wait (struct server_context *ctx, json_t *params)
+{
+	(void) ctx;
+	(void) params;
+
+	sleep (1);
+	return json_rpc_response (NULL, json_null (), NULL);
+}
+
 static json_t *
 json_rpc_date (struct server_context *ctx, json_t *params)
 {
@@ -1524,6 +1535,7 @@ process_json_rpc_request (struct server_context *ctx, json_t *request)
 		{ "date",         json_rpc_date     },
 		{ "ping",         json_rpc_ping     },
 		{ "rpc.discover", json_rpc_discover },
+		{ "wait",         json_rpc_wait     },
 	};
 
 	if (!json_is_object (request))