tests: virstringtest: adding tests to virStrToDouble()

There are no occurrences of tests related to Strings and Double numbers
inside virstringtest.c. This commit introduces some tests to validate the
conversion. The test does not include locale changes yet.
Signed-off-by: NJulio Faracco <jcfaracco@gmail.com>

tests/virstringtest.c

@@ -652,6 +652,48 @@ testStringToLong(const void *opaque)
 }
 
 
+struct stringToDoubleData {
+    const char *str;
+    const char *end_ptr;
+    double res;
+};
+
+/* This test checks if double strings are successfully converted to double
+ * number considering the byproduct string too. */
+static int
+testStringToDouble(const void *opaque)
+{
+    const struct stringToDoubleData *data = opaque;
+    int ret = -1;
+    char *end_ptr = NULL;
+    double res = 0;
+
+    /* end_ptr returns or a substring or an empty string.
+     * It never returns a NULL pointer. */
+    if ((ret = virStrToDouble(data->str,
+                              data->end_ptr ? &end_ptr : NULL,
+                              &res)) < 0) {
+        fprintf(stderr, "Convert error of '%s', expected '%lf'\n",
+                data->str, data->res);
+        return ret;
+    }
+
+    if (res != data->res) {
+        fprintf(stderr, "Returned '%lf', expected '%lf'\n",
+                res, data->res);
+        return -1;
+    }
+
+    /* Comparing substrings. */
+    if (STRNEQ_NULLABLE(end_ptr, data->end_ptr)) {
+        fprintf(stderr, "Expected substring '%s', but got '%s'\n",
+                end_ptr, data->end_ptr);
+        return -1;
+    }
+
+    return ret;
+}
+
 /* The point of this test is to check whether all members of the array are
  * freed. The test has to be checked using valgrind. */
 static int
@@ -965,6 +1007,44 @@ mymain(void)
     TEST_STRTOL("-18446744073709551616", NULL, 0, -1, 0U, -1,
                 0LL, -1, 0ULL, -1);
 
+#define TEST_STRTOD(str, end_ptr, res)                                  \
+    do {                                                                \
+        struct stringToDoubleData data = {                              \
+            str, end_ptr, res,                                          \
+        };                                                              \
+        if (virTestRun("virStringToDouble '" str "'",                   \
+                       testStringToDouble, &data) < 0)                  \
+            ret = -1;                                                   \
+    } while (0)
+
+    /* Simple numbers. */
+    TEST_STRTOD("0.0", NULL, 0);
+    TEST_STRTOD("1.0", NULL, 1);
+    TEST_STRTOD("3.14159", NULL, 3.14159);
+    TEST_STRTOD("0.57721", NULL, 0.57721);
+
+    /* Testing ending string. */
+    TEST_STRTOD("2.718", "", 2.718);
+    TEST_STRTOD("2.718 281 828 459", " 281 828 459", 2.718);
+    TEST_STRTOD("2.718,281,828,459", ",281,828,459", 2.718);
+
+    /* Scientific numbers. */
+    TEST_STRTOD("3.14159e+000", NULL, 3.14159);
+    TEST_STRTOD("2.00600e+003", NULL, 2006);
+    TEST_STRTOD("1.00000e-010", NULL, 1e-010);
+
+    /* Negative numbers. */
+    TEST_STRTOD("-1.6180339887", NULL, -1.6180339887);
+    TEST_STRTOD("-0.00031e-010", NULL, -0.00031e-010);
+
+    /* Long numbers. */
+    TEST_STRTOD("57089907708238388904078437636832797971793838081897.0",
+                NULL,
+                57089907708238388904078437636832797971793838081897.0);
+    TEST_STRTOD("3.141592653589793238462643383279502884197169399375105",
+                NULL,
+                3.141592653589793238462643383279502884197169399375105);
+
     /* test virStringListFreeCount */
     if (virTestRun("virStringListFreeCount", testVirStringListFreeCount,
                    NULL) < 0)