test: unit test for echo command

Provide a unit test for the unit command

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/test/cmd/test_echo.c b/test/cmd/test_echo.c
new file mode 100644
index 0000000..4183cf7
--- /dev/null
+++ b/test/cmd/test_echo.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Tests for echo command
+ *
+ * Copyright 2020, Heinrich Schuchadt <xypron.glpk@gmx.de>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <display_options.h>
+#include <test/lib.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct test_data {
+	char *cmd;
+	char *expected;
+};
+
+static struct test_data echo_data[] = {
+	{"echo 1 2 3",
+	 "1 2 3"},
+	/* Test new line handling */
+	{"echo -n 1 2 3; echo a b c",
+	 "1 2 3a b c"},
+	/*
+	 * Test handling of environment variables.
+	 *
+	 * j, q, x are among the least frequent letters in English.
+	 * Hence no collision for the variable name jQx is expected.
+	 */
+	{"setenv jQx X; echo \"a)\" ${jQx} 'b)' '${jQx}' c) ${jQx}; setenv jQx",
+	 "a) X b) ${jQx} c) X"},
+	/* Test handling of shell variables. */
+	{"setenv jQx; for jQx in 1 2 3; do echo -n \"${jQx}, \"; done; echo;",
+	 "1, 2, 3, "},
+};
+
+static int lib_test_hush_echo(struct unit_test_state *uts)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(echo_data); ++i) {
+		console_record_reset_enable();
+		ut_assertok(run_command(echo_data[i].cmd, 0));
+		gd->flags &= ~GD_FLG_RECORD;
+		console_record_readline(uts->actual_str,
+					sizeof(uts->actual_str));
+		ut_asserteq_str(echo_data[i].expected, uts->actual_str);
+		ut_assertok(ut_check_console_end(uts));
+	}
+	return 0;
+}
+
+LIB_TEST(lib_test_hush_echo, 0);