[test] Add test cases for editable strings

Signed-off-by: Michael Brown <mcb30@ipxe.org>
diff --git a/src/tests/editstring_test.c b/src/tests/editstring_test.c
new file mode 100644
index 0000000..72da33a
--- /dev/null
+++ b/src/tests/editstring_test.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (C) 2024 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program 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 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * Editable string tests
+ *
+ */
+
+/* Forcibly enable assertions */
+#undef NDEBUG
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <ipxe/keys.h>
+#include <ipxe/editstring.h>
+#include <ipxe/test.h>
+
+/** An editable string test */
+struct editstring_test {
+	/** Initial string, or NULL */
+	const char *start;
+	/** Key sequence */
+	const int *keys;
+	/** Length of key sequence */
+	unsigned int count;
+	/** Expected result */
+	const char *expected;
+};
+
+/** Define an inline key sequence */
+#define KEYS(...) { __VA_ARGS__ }
+
+/** Define an editable string test */
+#define EDITSTRING_TEST( name, START, EXPECTED, KEYS )			\
+	static const int name ## _keys[] = KEYS;			\
+	static struct editstring_test name = {				\
+		.start = START,						\
+		.keys = name ## _keys,					\
+		.count = ( sizeof ( name ## _keys ) /			\
+			   sizeof ( name ## _keys[0] ) ),		\
+		.expected = EXPECTED,					\
+	};
+
+/* Simple typing */
+EDITSTRING_TEST ( simple, "", "hello world!",
+		  KEYS ( 'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l',
+			 'd', '!' ) );
+
+/* Simple typing from a NULL starting value */
+EDITSTRING_TEST ( simple_null, NULL, "hi there",
+		  KEYS ( 'h', 'i', ' ', 't', 'h', 'e', 'r', 'e' ) );
+
+/* Insertion */
+EDITSTRING_TEST ( insert, "in middle", "in the middle",
+		  KEYS ( KEY_LEFT, KEY_LEFT, KEY_LEFT, KEY_LEFT, KEY_LEFT,
+			 KEY_LEFT, 't', 'h', 'e', ' ' ) );
+
+/* Backspace at end */
+EDITSTRING_TEST ( backspace_end, "byebye", "bye",
+		  KEYS ( KEY_BACKSPACE, KEY_BACKSPACE, KEY_BACKSPACE ) );
+
+/* Backspace of whole string */
+EDITSTRING_TEST ( backspace_all, "abc", "",
+		  KEYS ( KEY_BACKSPACE, KEY_BACKSPACE, KEY_BACKSPACE ) );
+
+/* Backspace of empty string */
+EDITSTRING_TEST ( backspace_empty, NULL, "", KEYS ( KEY_BACKSPACE ) );
+
+/* Backspace beyond start of string */
+EDITSTRING_TEST ( backspace_beyond, "too far", "",
+		  KEYS ( KEY_BACKSPACE, KEY_BACKSPACE, KEY_BACKSPACE,
+			 KEY_BACKSPACE, KEY_BACKSPACE, KEY_BACKSPACE,
+			 KEY_BACKSPACE, KEY_BACKSPACE, KEY_BACKSPACE ) );
+
+/* Deletion of character at cursor via DEL */
+EDITSTRING_TEST ( delete_dc, "go away", "goaway",
+		  KEYS ( KEY_HOME, KEY_RIGHT, KEY_RIGHT, KEY_DC ) );
+
+/* Deletion of character at cursor via Ctrl-D */
+EDITSTRING_TEST ( delete_ctrl_d, "not here", "nohere",
+		  KEYS ( KEY_LEFT, KEY_LEFT, KEY_LEFT, KEY_LEFT, KEY_LEFT,
+			 KEY_LEFT, CTRL_D, CTRL_D ) );
+
+/* Deletion of word at end of string */
+EDITSTRING_TEST ( word_end, "remove these two words", "remove these ",
+		  KEYS ( CTRL_W, CTRL_W ) );
+
+/* Deletion of word at start of string */
+EDITSTRING_TEST ( word_start, "no word", "word",
+		  KEYS ( CTRL_A, KEY_RIGHT, KEY_RIGHT, KEY_RIGHT, CTRL_W ) );
+
+/* Deletion of word mid-string */
+EDITSTRING_TEST ( word_mid, "delete this word", "delete word",
+		  KEYS ( KEY_LEFT, KEY_LEFT, KEY_LEFT, KEY_LEFT, CTRL_W ) );
+
+/* Deletion to start of line */
+EDITSTRING_TEST ( sol, "everything must go", "go",
+		  KEYS ( KEY_LEFT, KEY_LEFT, CTRL_U ) );
+
+/* Delete to end of line */
+EDITSTRING_TEST ( eol, "all is lost", "all",
+		  KEYS ( KEY_HOME, KEY_RIGHT, KEY_RIGHT, KEY_RIGHT, CTRL_K ) );
+
+/**
+ * Report an editable string test result
+ *
+ * @v test		Editable string test
+ * @v file		Test code file
+ * @v line		Test code line
+ */
+static void editstring_okx ( struct editstring_test *test, const char *file,
+			     unsigned int line ) {
+	struct edit_string string;
+	unsigned int i;
+	char *actual;
+	int key;
+
+	/* Initialise editable string */
+	memset ( &string, 0, sizeof ( string ) );
+	actual = NULL;
+	init_editstring ( &string, &actual );
+
+	/* Set initial string content */
+	okx ( replace_string ( &string, test->start ) == 0, file, line );
+	okx ( actual != NULL, file, line );
+	okx ( string.cursor == ( test->start ? strlen ( test->start ) : 0 ),
+	      file, line );
+	DBGC ( test, "Initial string: \"%s\"\n", actual );
+
+	/* Inject keypresses */
+	for ( i = 0 ; i < test->count ; i++ ) {
+		key = test->keys[i];
+		okx ( edit_string ( &string, key ) == 0, file, line );
+		okx ( actual != NULL, file, line );
+		okx ( string.cursor <= strlen ( actual ), file, line );
+		DBGC ( test, "After key %#02x (%c): \"%s\"\n",
+		       key, ( isprint ( key ) ? key : '.' ), actual );
+	}
+
+	/* Verify result string */
+	okx ( strcmp ( actual, test->expected ) == 0, file, line );
+
+	/* Free result string */
+	free ( actual );
+}
+#define editstring_ok( test ) editstring_okx ( test, __FILE__, __LINE__ )
+
+/**
+ * Perform editable string self-tests
+ *
+ */
+static void editstring_test_exec ( void ) {
+
+	editstring_ok ( &simple );
+	editstring_ok ( &simple_null );
+	editstring_ok ( &insert );
+	editstring_ok ( &backspace_end );
+	editstring_ok ( &backspace_all );
+	editstring_ok ( &backspace_empty );
+	editstring_ok ( &backspace_beyond );
+	editstring_ok ( &delete_dc );
+	editstring_ok ( &delete_ctrl_d );
+	editstring_ok ( &word_end );
+	editstring_ok ( &word_start );
+	editstring_ok ( &word_mid );
+	editstring_ok ( &sol );
+	editstring_ok ( &eol );
+}
+
+/** Editable string self-test */
+struct self_test editstring_test __self_test = {
+	.name = "editstring",
+	.exec = editstring_test_exec,
+};
diff --git a/src/tests/tests.c b/src/tests/tests.c
index cb29604..0e9b3e8 100644
--- a/src/tests/tests.c
+++ b/src/tests/tests.c
@@ -85,3 +85,4 @@
 REQUIRE_OBJECT ( des_test );
 REQUIRE_OBJECT ( mschapv2_test );
 REQUIRE_OBJECT ( uuid_test );
+REQUIRE_OBJECT ( editstring_test );