Fix for #585. Make fromEnvironment tests to be independed from defaultValue

Author: sgrekhov

LibTest/core/String/String.fromEnvironment_A01_t01.dart

@@ -16,11 +16,16 @@
  */
 import "../../../Utils/expect.dart";
 
+const ENV_VAR = "SOME_ENV_VARIABLE";
+
 main() {
-  var s1 = new String.fromEnvironment("SOME_ENV_VARIABLE",
-      defaultValue: "No");
-  Expect.equals("No", s1);
+  const def1 = bool.hasEnvironment(ENV_VAR) ? const String.fromEnvironment(ENV_VAR) : "No";
+  var s1 = const String.fromEnvironment(ENV_VAR, defaultValue: def1);
+  Expect.equals(def1, s1);
 
-  var s2 = new String.fromEnvironment("SOME_ENV_VARIABLE");
-  Expect.isNull(s2);
+  const def2 = bool.hasEnvironment(ENV_VAR) ? const String.fromEnvironment(ENV_VAR) : null;
+  var s2 = const bool.hasEnvironment(ENV_VAR)
+      ? String.fromEnvironment(ENV_VAR)
+      : def2;
+  Expect.equals(def2, s2);
 }

LibTest/core/bool/bool.fromEnvironment_A01_t01.dart

@@ -15,7 +15,10 @@
  */
 import "../../../Utils/expect.dart";
 
+const ENV_VAR = "SOME_ENV_VARIABLE";
+
 main() {
-  const someFlag = const bool.fromEnvironment("someFlag");
-  Expect.isFalse(someFlag);
+  const def1 = bool.hasEnvironment(ENV_VAR) ? const bool.fromEnvironment(ENV_VAR) : false;
+  var b = bool.hasEnvironment(ENV_VAR) ? const bool.fromEnvironment(ENV_VAR) : def1;
+  Expect.equals(def1, b);
 }

LibTest/core/int/int.fromEnvironment_A01_t01.dart

@@ -7,15 +7,22 @@
  * @assertion const int.fromEnvironment(String name, {int defaultValue})
  * Returns the integer value of the given environment declaration name.
  * The result is the same as would be returned by:
- * int.parse(const String.fromEnvironment(name, defaultValue: ""),
- * (_) => defaultValue)
+ * int.tryParse(const String.fromEnvironment(name, defaultValue: ""))
+ *   ?? defaultValue
  * @description Checks that this constructor returns null if there is no
  * environment variable with appropriate name
  * @author [email protected]
  */
 import "../../../Utils/expect.dart";
 
+const ENV_VAR = "SOME_ENV_VARIABLE";
+
 main() {
-  const someFlag = const int.fromEnvironment("someFlag");
-  Expect.isNull(someFlag);
+  const def1 = bool.hasEnvironment(ENV_VAR) ? const int.fromEnvironment(ENV_VAR) : null;
+  const v1 = bool.hasEnvironment(ENV_VAR) ? const int.fromEnvironment(ENV_VAR) : def1;
+  Expect.equals(def1, v1);
+
+  const def2 = bool.hasEnvironment(ENV_VAR) ? const int.fromEnvironment(ENV_VAR) : 42;
+  const v2 = const int.fromEnvironment(ENV_VAR, defaultValue: def2);
+  Expect.equals(def2, v2);
 }