add leap exercise (#20)

* add leap exercise

* update

* for testing

config.json

@@ -44,6 +44,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 1
+      },
+      {
+        "slug": "leap",
+        "name": "Leap",
+        "uuid": "ed451561-a84a-4b44-a3c9-9a0d9378667c",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
       }
     ]
   },

exercises/practice/leap/.docs/instructions.md

@@ -0,0 +1,24 @@
+# Description
+
+Given a year, report if it is a leap year.
+
+The tricky thing here is that a leap year in the Gregorian calendar occurs:
+
+```text
+on every year that is evenly divisible by 4
+  except every year that is evenly divisible by 100
+    unless the year is also evenly divisible by 400
+```
+
+For example, 1997 is not a leap year, but 1996 is.  1900 is not a leap
+year, but 2000 is.
+
+## Notes
+
+Though our exercise adopts some very simple rules, there is more to
+learn!
+
+For a delightful, four minute explanation of the whole leap year
+phenomenon, go watch [this youtube video][video].
+
+[video]: http://www.youtube.com/watch?v=xX96xng7sAE

exercises/practice/leap/.meta/config.json

@@ -0,0 +1,13 @@
+{
+  "blurb": "Given a year, report if it is a leap year.",
+  "authors": ["larshp"],
+  "contributors": [
+  ],
+  "files": {
+    "solution": ["zcl_leap.clas.abap"],
+    "test": ["zcl_leap.clas.testclasses.abap"],
+    "example": [".meta/zcl_leap.clas.abap"]
+  },
+  "source": "JavaRanch Cattle Drive, exercise 3",
+  "source_url": "http://www.javaranch.com/leap.jsp"
+}

exercises/practice/leap/.meta/zcl_leap.clas.abap

@@ -0,0 +1,22 @@
+CLASS zcl_leap DEFINITION PUBLIC.
+  PUBLIC SECTION.
+    METHODS leap
+      IMPORTING
+        year         TYPE i
+      RETURNING
+        VALUE(result) TYPE abap_bool.
+ENDCLASS.
+
+CLASS zcl_leap IMPLEMENTATION.
+
+  METHOD leap.
+    IF year MOD 4 = 0 AND year MOD 100 <> 0.
+      result = abap_true.
+    ELSEIF year MOD 400 = 0.
+      result = abap_true.
+    ELSE.
+      result = abap_false.
+    ENDIF.
+  ENDMETHOD.
+
+ENDCLASS.

exercises/practice/leap/zcl_leap.clas.abap

@@ -0,0 +1,16 @@
+CLASS zcl_leap DEFINITION PUBLIC.
+  PUBLIC SECTION.
+    METHODS leap
+      IMPORTING
+        year          TYPE i
+      RETURNING
+        VALUE(result) TYPE abap_bool.
+ENDCLASS.
+
+CLASS zcl_leap IMPLEMENTATION.
+
+  METHOD leap.
+* add solution here
+  ENDMETHOD.
+
+ENDCLASS.

exercises/practice/leap/zcl_leap.clas.testclasses.abap

@@ -0,0 +1,87 @@
+CLASS ltcl_leap DEFINITION FOR TESTING RISK LEVEL HARMLESS DURATION SHORT FINAL.
+
+  PRIVATE SECTION.
+    DATA cut TYPE REF TO zcl_leap.
+    METHODS setup.
+    METHODS test_2015 FOR TESTING.
+    METHODS test_1970 FOR TESTING.
+    METHODS test_1996 FOR TESTING.
+    METHODS test_1960 FOR TESTING.
+    METHODS test_2100 FOR TESTING.
+    METHODS test_1900 FOR TESTING.
+    METHODS test_2000 FOR TESTING.
+    METHODS test_2400 FOR TESTING.
+    METHODS test_1800 FOR TESTING.
+
+ENDCLASS.
+
+CLASS ltcl_leap IMPLEMENTATION.
+
+  METHOD setup.
+    cut = NEW zcl_leap( ).
+  ENDMETHOD.
+
+  METHOD test_2015.
+* year not divisible by 4 in common year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 2015 )
+      exp = abap_false ).
+  ENDMETHOD.
+
+  METHOD test_1970.
+* year divisible by 2, not divisible by 4 in common year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 1970 )
+      exp = abap_false ).
+  ENDMETHOD.
+
+  METHOD test_1996.
+* year divisible by 4, not divisible by 100 in leap year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 1996 )
+      exp = abap_true ).
+  ENDMETHOD.
+
+  METHOD test_1960.
+* year divisible by 4 and 5 is still a leap year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 1960 )
+      exp = abap_true ).
+  ENDMETHOD.
+
+  METHOD test_2100.
+* year divisible by 100, not divisible by 400 in common year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 2100 )
+      exp = abap_false ).
+  ENDMETHOD.
+
+  METHOD test_1900.
+* year divisible by 100 but not by 3 is still not a leap year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 1900 )
+      exp = abap_false ).
+  ENDMETHOD.
+
+  METHOD test_2000.
+* year divisible by 400 is leap year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 2000 )
+      exp = abap_true ).
+  ENDMETHOD.
+
+  METHOD test_2400.
+* year divisible by 400 but not by 125 is still a leap year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 2400 )
+      exp = abap_true ).
+  ENDMETHOD.
+
+  METHOD test_1800.
+* year divisible by 200, not divisible by 400 in common year
+    cl_abap_unit_assert=>assert_equals(
+      act = cut->leap( 1800 )
+      exp = abap_false ).
+  ENDMETHOD.
+
+ENDCLASS.