Re: [dpdk-dev] [PATCH v5 2/3] test/test_telemetry_data: add unit tests for data to JSON

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Jul 15, 2020 at 01:29:34PM +0100, Ciara Power wrote:
> From: Louise Kilheeney <louise.kilheeney@intel.com>
> 
> This patch adds tests for verifying telemetry data structures are
> converted to JSON as expected. Both flat and recursive data structures
> are tested, for all possible value types.
> 
> Signed-off-by: Louise Kilheeney <louise.kilheeney@intel.com>
> Signed-off-by: Ciara Power <ciara.power@intel.com>

Great to see some unit tests included. However, I think the documenting of
what is happening is missing in comments and in the commit log. I think you
need to explain in the commit log the general pattern used for the tests,
which seems to be having a different response copied to the user each time
the callback is called, and verifing that the output got is what was
built-up internally. 
This should also be explained via comments in the code too, as I call out
below.

> ---
>  app/test/Makefile              |   1 +
>  app/test/meson.build           |   5 +-
>  app/test/test_telemetry_data.c | 359 +++++++++++++++++++++++++++++++++
>  3 files changed, 363 insertions(+), 2 deletions(-)
>  create mode 100644 app/test/test_telemetry_data.c
> 
> diff --git a/app/test/Makefile b/app/test/Makefile
> index f4065271e..1cb64089c 100644
> --- a/app/test/Makefile
> +++ b/app/test/Makefile
> @@ -145,6 +145,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_LPM) += test_lpm6.c
>  SRCS-$(CONFIG_RTE_LIBRTE_LPM) += test_lpm6_perf.c
>  
>  SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += test_telemetry_json.c
> +SRCS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += test_telemetry_data.c
>  
>  SRCS-y += test_debug.c
>  SRCS-y += test_errno.c
> diff --git a/app/test/meson.build b/app/test/meson.build
> index 786a21397..4a72fe5b6 100644
> --- a/app/test/meson.build
> +++ b/app/test/meson.build
> @@ -170,6 +170,7 @@ test_deps = ['acl',
>  	'ring',
>  	'security',
>  	'stack',
> +	'telemetry',
>  	'timer'
>  ]
>  
> @@ -345,8 +346,8 @@ if dpdk_conf.has('RTE_LIBRTE_SKELETON_EVENTDEV_PMD')
>  	test_deps += 'pmd_skeleton_event'
>  endif
>  if dpdk_conf.has('RTE_LIBRTE_TELEMETRY')
> -	test_sources += 'test_telemetry_json.c'
> -	fast_tests += [['telemetry_json_autotest', true]]
> +	test_sources += ['test_telemetry_json.c', 'test_telemetry_data.c']
> +	fast_tests += [['telemetry_json_autotest', true], ['telemetry_data_autotest', true]]
>  endif
>  
>  # The following linkages of drivers are required because
> diff --git a/app/test/test_telemetry_data.c b/app/test/test_telemetry_data.c
> new file mode 100644
> index 000000000..670af9134
> --- /dev/null
> +++ b/app/test/test_telemetry_data.c
> @@ -0,0 +1,359 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Intel Corporation
> + */
> +
> +#include <glob.h>
> +#include <string.h>
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +#include <unistd.h>
> +#include <limits.h>
> +
> +#include <rte_eal.h>
> +#include <rte_common.h>
> +#include <rte_telemetry.h>
> +#include <rte_string_fns.h>
> +
> +#include "test.h"
> +#include "telemetry_data.h"
> +
> +#define TELEMETRY_VERSION "v2"
> +#define REQUEST_CMD "/test"
> +#define BUF_SIZE 1024
> +#define TEST_OUTPUT(exp) test_output(__func__, exp)
> +
> +static struct rte_tel_data response_data;
> +static int sock;
> +
> +static int
> +test_cb(const char *cmd __rte_unused, const char *params __rte_unused,
> +		struct rte_tel_data *d)
> +{
> +	*d = response_data;
> +	return 0;
> +}

This function needs a comment explaining what it does and why.

> +
> +static int
> +test_output(const char *func_name, const char *expected)
> +{
> +	int bytes;
> +	char buf[BUF_SIZE * 16];
> +	if (write(sock, REQUEST_CMD, strlen(REQUEST_CMD)) < 0) {
> +		printf("%s: Error with socket write - %s\n", __func__,
> +				strerror(errno));
> +		return -1;
> +	}
> +	bytes = read(sock, buf, sizeof(buf));
> +	if (bytes < 0) {
> +		printf("%s: Error with socket read - %s\n", __func__,
> +				strerror(errno));
> +		return -1;
> +	}
> +	buf[bytes] = '\0';
> +	printf("%s: buf = '%s', expected = '%s'\n", func_name, buf, expected);
> +	return strncmp(expected, buf, sizeof(buf));
> +}
> +

This one too, needs comment explaining how it works etc.

<snip>
> +static int
> +test_telemetry_data(void)
> +{
> +	sock = connect_to_socket();
> +	if (sock <= 0)
> +		return -1;
> +
> +	rte_telemetry_register_cmd(REQUEST_CMD, test_cb, "Test");
> +	if (test_case_array_string() != 0
> +	|| test_case_array_int() != 0
> +	|| test_case_array_u64() != 0
> +	|| test_case_add_dict_int() != 0
> +	|| test_case_add_dict_u64() != 0
> +	|| test_case_add_dict_string() != 0
> +	||  test_dict_with_array_int_values() != 0
> +	|| test_dict_with_array_u64_values() != 0
> +	|| test_dict_with_array_string_values() != 0
> +	|| test_array_with_array_int_values() != 0
> +	|| test_array_with_array_u64_values() != 0
> +	|| test_array_with_array_string_values() != 0) {
> +		close(sock);
> +		return -1;
> +	}

I'm not sure I like this way of calling the test cases, and the indentation
of the lines is definitely wrong. The simplest option here is to have a
single if statement for each test and a goto for the "error" leg:

	if (test_case_array_string() != 0)
	   goto error;
	if (test_case_array_int() != 0)
	   goto error;
	...

However, if you want to avoid the multiple if statements, a better option
than merging as above would be to put the functions in an array and loop
over them as (rough code, completely untested!):

	typedef int (*test_case)(void);

	test_case test_cases[] = {test_case_array_string,
			test_case_array_int, ... };
	...
	for (i = 0; i < RTE_DIM(test_cases); i++)
		if (test_cases[i]() != 0) {
			...
		}

> +
> +	close(sock);
> +	return 0;
> +}
> +
> +REGISTER_TEST_COMMAND(telemetry_data_autotest, test_telemetry_data);
> -- 

Regards,
/Bruce