Simplify string comparisons in tests and fix bug in String::compareTo

api/String.cpp

@@ -462,7 +462,7 @@ int String::compareTo(const String &s) const
 int String::compareTo(const char *cstr) const
 {
 	if (!buffer || !cstr) {
-		if (cstr && !*cstr) return 0 - *(unsigned char *)cstr;
+		if (cstr && *cstr) return 0 - *(unsigned char *)cstr;
 		if (buffer && len > 0) return *(unsigned char *)buffer;
 		return 0;
 	}

test/src/String/StringPrinter.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <catch.hpp>
+#include <String.h>
+
+namespace Catch {
+  /**
+   * Template specialization that makes sure Catch can properly print
+   * Arduino Strings when used in comparisons directly.
+   *
+   * Note that without this, String objects are printed as 0 and 1,
+   * because they are implicitly convertible to StringIfHelperType,
+   * which is a dummy pointer.
+   */
+  template<>
+  struct StringMaker<arduino::String> {
+      static std::string convert(const arduino::String& str) {
+	if (str)
+	  return ::Catch::Detail::stringify(std::string(str.c_str(), str.length()));
+	else
+	  return "{invalid String}";
+      }
+  };
+} // namespace Catch

test/src/String/test_String.cpp

@@ -12,6 +12,8 @@
 
 #include <String.h>
 
+#include "StringPrinter.h"
+
 /**************************************************************************************
  * TEST CODE
  **************************************************************************************/
@@ -20,82 +22,82 @@ TEST_CASE ("Testing String(const char *) constructor()", "[String-Ctor-01]")
 {
   char const CSTR[] = "Hello Arduino String Class";
   arduino::String str(CSTR);
-  REQUIRE(strcmp(CSTR, str.c_str()) == 0);
+  REQUIRE(str == CSTR);
 }
 
 TEST_CASE ("Testing String(const String &) constructor()", "[String-Ctor-02]")
 {
   arduino::String str1("Hello Arduino String class"),
                   str2(str1);
-  REQUIRE(strcmp(str1.c_str(), str2.c_str()) == 0);
+  REQUIRE(str1 == str2);
 }
 
 TEST_CASE ("Testing String(const __FlashStringHelper) constructor()", "[String-Ctor-03]")
 {
 #undef F
 #define F(string_literal) (reinterpret_cast<const arduino::__FlashStringHelper *>(PSTR(string_literal)))
   arduino::String str1(F("Hello"));
-  REQUIRE(str1.compareTo("Hello") == 0);
+  REQUIRE(str1 == "Hello");
 }
 
 TEST_CASE ("Testing String(char) constructor()", "[String-Ctor-04]")
 {
   char const ch = 'A';
   arduino::String str(ch);
-  REQUIRE(strcmp(str.c_str(), "A") == 0);
+  REQUIRE(str == "A");
 }
 
 TEST_CASE ("Testing String(unsigned char, unsigned char base = 10) constructor()", "[String-Ctor-05]")
 {
   unsigned char const val = 1;
   arduino::String str(val);
-  REQUIRE(strcmp(str.c_str(), "1") == 0);
+  REQUIRE(str == "1");
 }
 
 TEST_CASE ("Testing String(int, unsigned char base = 10) constructor()", "[String-Ctor-06]")
 {
   int const val = -1;
   arduino::String str(val);
-  REQUIRE(strcmp(str.c_str(), "-1") == 0);
+  REQUIRE(str == "-1");
 }
 
 TEST_CASE ("Testing String(unsigned int, unsigned char base = 10) constructor()", "[String-Ctor-07]")
 {
   unsigned int const val = 1;
   arduino::String str(val);
-  REQUIRE(strcmp(str.c_str(), "1") == 0);
+  REQUIRE(str == "1");
 }
 
 TEST_CASE ("Testing String(long, unsigned char base = 10) constructor()", "[String-Ctor-08]")
 {
   long const val = -1;
   arduino::String str(val);
-  REQUIRE(strcmp(str.c_str(), "-1") == 0);
+  REQUIRE(str == "-1");
 }
 
 TEST_CASE ("Testing String(unsigned long, unsigned char base = 10) constructor()", "[String-Ctor-09]")
 {
   unsigned long const val = 1;
   arduino::String str(val);
-  REQUIRE(strcmp(str.c_str(), "1") == 0);
+  REQUIRE(str == "1");
 }
 
 TEST_CASE ("Testing String(float, unsigned char decimalPlaces = 2) constructor()", "[String-Ctor-10]")
 {
   WHEN ("String::String (some float value)")
   {
     arduino::String str(1.234f);
-    REQUIRE(strcmp(str.c_str(), "1.23") == 0);
+    REQUIRE(str == "1.23");
   }
   WHEN ("String::String (FLT_MAX)")
   {
     arduino::String str(FLT_MAX);
-    REQUIRE(strcmp(str.c_str(), "340282346638528859811704183484516925440.00") == 0);
+    REQUIRE(str == "340282346638528859811704183484516925440.00");
   }
   WHEN ("String::String (-FLT_MAX)")
   {
     arduino::String str(-FLT_MAX);
-    REQUIRE(strcmp(str.c_str(), "-340282346638528859811704183484516925440.00") == 0);
+    REQUIRE(str == "-340282346638528859811704183484516925440.00");
   }
 }
 
@@ -104,17 +106,17 @@ TEST_CASE ("Testing String(double, unsigned char decimalPlaces = 2) constructor(
   WHEN ("String::String (some double value)")
   {
     arduino::String str(5.678);
-    REQUIRE(strcmp(str.c_str(), "5.68") == 0);
+    REQUIRE(str == "5.68");
   }
   WHEN ("String::String (DBL_MAX)")
   {
     arduino::String str(DBL_MAX);
-    REQUIRE(strcmp(str.c_str(), "179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.00") == 0);
+    REQUIRE(str == "179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.00");
   }
   WHEN ("String::String (-DBL_MAX)")
   {
     arduino::String str(-DBL_MAX);
-    REQUIRE(strcmp(str.c_str(), "-179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.00") == 0);
+    REQUIRE(str == "-179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.00");
   }
 }
 
@@ -125,36 +127,36 @@ TEST_CASE ("Testing String(const __FlashStringHelper) constructor() with invalid
   char *buffer = NULL;
 
   arduino::String str1(F(buffer));
-  REQUIRE(str1.compareTo("Hello") == 0);
+  REQUIRE_FALSE(str1);
 }
 
 TEST_CASE ("Testing String(StringSumHelper &&) constructor()", "[String-Ctor-13]")
 {
   arduino::String str("Hello");
   char const ch = '!';
   arduino::String str1(static_cast<arduino::StringSumHelper&&>(str+ch));
-  REQUIRE(str1.compareTo("Hello!") == 0);
+  REQUIRE(str1 == "Hello!");
 }
 
 TEST_CASE ("Testing String(String &&) constructor()", "[String-Ctor-14]")
 {
   arduino::String str("Hello");
   arduino::String str1(static_cast<arduino::String&&>(str));
-  REQUIRE(str1.compareTo("Hello") == 0);
+  REQUIRE(str1 == "Hello");
 }
 
 TEST_CASE ("Testing String(String &&) with move(String &rhs) from smaller to larger buffer", "[String-Ctor-15]")
 {
   arduino::String str("Hello");
   arduino::String str1("Arduino");
   str1 = static_cast<arduino::String&&>(str);
-  REQUIRE(str1.compareTo("Hello") == 0);
+  REQUIRE(str1 == "Hello");
 }
 
 TEST_CASE ("Testing String(String &&) with move(String &rhs) from larger to smaller buffer", "[String-Ctor-16]")
 {
   arduino::String str("Hello");
   arduino::String str1("Arduino");
   str = static_cast<arduino::String&&>(str1);
-  REQUIRE(str1.compareTo("Arduino") == 0);
+  REQUIRE(str == "Arduino");
 }

test/src/String/test_characterAccessFunc.cpp

@@ -10,6 +10,8 @@
 
 #include <String.h>
 
+#include "StringPrinter.h"
+
 /**************************************************************************************
  * TEST CODE
  **************************************************************************************/
@@ -24,7 +26,7 @@ TEST_CASE ("Testing String::setCharAt(unsigned int, char )", "[String-setCharAt-
 {
   arduino::String str1("Hello");
   str1.setCharAt(1, 'a');
-  REQUIRE(str1.compareTo("Hallo") == 0);
+  REQUIRE(str1 == "Hallo");
 }
 
 TEST_CASE ("Testing String::getBytes(unsigned char, unsigned int, unsigned int)", "[String-getBytes-02]")

test/src/String/test_compareTo.cpp

@@ -10,6 +10,8 @@
 
 #include <String.h>
 
+#include "StringPrinter.h"
+
 /**************************************************************************************
  * TEST CODE
  **************************************************************************************/

test/src/String/test_comparisonFunc.cpp

@@ -10,6 +10,8 @@
 
 #include <String.h>
 
+#include "StringPrinter.h"
+
 /**************************************************************************************
  * TEST CODE
  **************************************************************************************/
@@ -20,24 +22,72 @@ TEST_CASE ("Testing String::equals(const String &) with exit status PASS", "[Str
   REQUIRE(str1.equals(str2) == 1);
 }
 
+TEST_CASE ("Testing String::operator==(const String &) with exit status PASS", "[String-equals-01]")
+{
+  arduino::String str1("Hello"), str2("Hello");
+  REQUIRE(str1 == str2);
+}
+
+TEST_CASE ("Testing String::operator!=(const String &) with exit status FAIL", "[String-equals-01]")
+{
+  arduino::String str1("Hello"), str2("Hello");
+  REQUIRE_FALSE(str1 != str2);
+}
+
 TEST_CASE ("Testing String::equals(const String &) with exit status FAIL", "[String-equals-02]")
 {
   arduino::String str1("Hello"), str2("World");
   REQUIRE(str1.equals(str2) == 0);
 }
 
+TEST_CASE ("Testing String::operator==(const String &) with exit status FAIL", "[String-equals-02]")
+{
+  arduino::String str1("Hello"), str2("World");
+  REQUIRE_FALSE(str1 == str2);
+}
+
+TEST_CASE ("Testing String::operator !=(const String &) with exit status PASS", "[String-equals-02]")
+{
+  arduino::String str1("Hello"), str2("World");
+  REQUIRE(str1 != str2);
+}
+
 TEST_CASE ("Testing String::equals(const char *) with exit status PASS", "[String-equals-03]")
 {
   arduino::String str1("Hello");
   REQUIRE(str1.equals("Hello") == 1);
 }
 
+TEST_CASE ("Testing String::operator ==(const char *) with exit status PASS", "[String-equals-03]")
+{
+  arduino::String str1("Hello");
+  REQUIRE(str1 == "Hello");
+}
+
+TEST_CASE ("Testing String::operator !=(const char *) with exit status FAIL", "[String-equals-03]")
+{
+  arduino::String str1("Hello");
+  REQUIRE_FALSE(str1 != "Hello");
+}
+
 TEST_CASE ("Testing String::equals(const char *) with exit status FAIL", "[String-equals-04]")
 {
   arduino::String str1("Hello");
   REQUIRE(str1.equals("World") == 0);
 }
 
+TEST_CASE ("Testing String::operator ==(const char *) with exit status FAIL", "[String-equals-04]")
+{
+  arduino::String str1("Hello");
+  REQUIRE_FALSE(str1 == "World");
+}
+
+TEST_CASE ("Testing String::operator !=(const char *) with exit status PASS", "[String-equals-04]")
+{
+  arduino::String str1("Hello");
+  REQUIRE(str1 != "World");
+}
+
 TEST_CASE ("Testing String::equalsIgnoreCase(const String &) PASS with NON-empty string", "[String-equalsIgnoreCase-05]")
 {
   arduino::String str1("Hello"), str2("Hello");
@@ -104,4 +154,4 @@ TEST_CASE ("Testing String::endsWith(const String &)", "[String-endsWith-10]")
     arduino::String str2("Helo");
     REQUIRE(str1.endsWith(str2) == 0);
   }
-}
+}