feat: mp_sortinplace and corresponding test. Closes #102.

tests/crossplatform/mp_sortinplace.test.sas

@@ -0,0 +1,42 @@
+/**
+  @file
+  @brief Testing mp_sortinplace.test.sas
+
+  <h4> SAS Macros </h4>
+  @li mp_sortinplace.sas
+  @li mp_assert.sas
+  @li mp_assertdsobs.sas
+  @li mp_getconstraints.sas
+
+**/
+
+
+/** Test 1 - regular usage  */
+proc sql;
+create table work.example as
+  select * from sashelp.classfit;
+alter table work.example
+  add constraint pk primary key(name);
+%mp_sortinplace(work.example)
+
+%mp_getconstraints(lib=work,ds=example,outds=work.testme)
+
+%mp_assertdsobs(work.testme,
+  desc=Test1 - check constraints recreated,
+  test=EQUALS 1,
+  outds=work.test_results
+)
+
+%let test1=0;
+data _null_;
+  set work.example;
+  call symputx('test1',name);
+  stop;
+run;
+%mp_assert(
+  iftrue=(
+    %str(&test1)=%str(Alfred)
+  ),
+  desc=Check if sort was appplied,
+  outds=work.test_results
+)