lib/upytesthelper: MicroPython test helper layer on top of tinytest.

Tinytest is classical assert-style framework, but MicroPython tests work
in different way - they produce content, and that content should be matched
against expected one to see if test passes. upytesthelper exactly adds
helper functions to make that possible.

lib/upytesthelper/upytesthelper.c

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include <string.h>
+
+#include "py/mphal.h"
+#include "py/gc.h"
+#include "py/runtime.h"
+#include "py/compile.h"
+#include "upytesthelper.h"
+
+static const char *test_exp_output;
+static int test_exp_output_len, test_rem_output_len;
+static int test_failed;
+static void *heap_start, *heap_end;
+
+void upytest_set_heap(void *start, void *end) {
+    heap_start = start;
+    heap_end = end;
+}
+
+void upytest_set_expected_output(const char *output, unsigned len) {
+    test_exp_output = output;
+    test_exp_output_len = test_rem_output_len = len;
+    test_failed = false;
+}
+
+bool upytest_is_failed(void) {
+    if (test_failed) {
+        return true;
+    }
+    #if 0
+    if (test_rem_output_len != 0) {
+        printf("remaining len: %d\n", test_rem_output_len);
+    }
+    #endif
+    return test_rem_output_len != 0;
+}
+
+// MP_PLAT_PRINT_STRN() should be redirected to this function.
+// It will pass-thru any content to mp_hal_stdout_tx_strn_cooked()
+// (the dfault value of MP_PLAT_PRINT_STRN), but will also match
+// it to the expected output as set by upytest_set_expected_output().
+// If mismatch happens, upytest_is_failed() returns true.
+void upytest_output(const char *str, mp_uint_t len) {
+    if (!test_failed) {
+        if (len > test_rem_output_len) {
+            test_failed = true;
+        } else {
+            test_failed = memcmp(test_exp_output, str, len);
+            #if 0
+            if (test_failed) {
+                printf("failed after char %u, within %d chars, res: %d\n",
+                    test_exp_output_len - test_rem_output_len, (int)len, test_failed);
+                for (int i = 0; i < len; i++) {
+                    if (str[i] != test_exp_output[i]) {
+                        printf("%d %02x %02x\n", i, str[i], test_exp_output[i]);
+                    }
+                }
+            }
+            #endif
+            test_exp_output += len;
+            test_rem_output_len -= len;
+        }
+    }
+    mp_hal_stdout_tx_strn_cooked(str, len);
+}
+
+void upytest_execute_test(const char *src) {
+    // To provide clean room for each test, interpreter and heap are
+    // reinitialized before running each.
+    gc_init(heap_start, heap_end);
+    mp_init();
+    mp_obj_list_init(mp_sys_path, 0);
+    mp_obj_list_init(mp_sys_argv, 0);
+
+    nlr_buf_t nlr;
+    if (nlr_push(&nlr) == 0) {
+        mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, src, strlen(src), 0);
+        qstr source_name = lex->source_name;
+        mp_parse_tree_t parse_tree = mp_parse(lex, MP_PARSE_FILE_INPUT);
+        mp_obj_t module_fun = mp_compile(&parse_tree, source_name, MP_EMIT_OPT_NONE, false);
+        mp_call_function_0(module_fun);
+        nlr_pop();
+    } else {
+        mp_obj_t exc = (mp_obj_t)nlr.ret_val;
+        if (mp_obj_is_subclass_fast(mp_obj_get_type(exc), &mp_type_SystemExit)) {
+            // Assume that sys.exit() is called to skip the test.
+            // TODO: That can be always true, we should set up convention to
+            // use specific exit code as skip indicator.
+            tinytest_set_test_skipped_();
+            goto end;
+        }
+        mp_obj_print_exception(&mp_plat_print, exc);
+        tt_abort_msg("Uncaught exception\n");
+    }
+
+    if (upytest_is_failed()) {
+        tinytest_set_test_failed_();
+    }
+
+end:
+    mp_deinit();
+}

lib/upytesthelper/upytesthelper.h

+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include "py/mpconfig.h"
+#include "lib/tinytest/tinytest.h"
+#include "lib/tinytest/tinytest_macros.h"
+
+void upytest_set_heap(void *start, void *end);
+void upytest_set_expected_output(const char *output, unsigned len);
+void upytest_execute_test(const char *src);
+void upytest_output(const char *str, mp_uint_t len);
+bool upytest_is_failed(void);