Add type checking tests for conditions

Author: rexim

tests/.gitignore

@@ -7,4 +7,6 @@ stack
 comments
 macros
 dead-recursive-macro
-argv
+argv
+if-else
+else-less-if

tests/else-less-if-fail.porth

@@ -0,0 +1 @@
+34 35 + 69 = if 69 end print

tests/else-less-if-fail.txt

@@ -0,0 +1,11 @@
+:i argc 0
+:b stdin 0
+
+:i returncode 1
+:b stdout 0
+
+:b stderr 274
+./tests/else-less-if-fail.porth:1:20: ERROR: else-less if block is not allowed to alter the types of the arguments on the data stack
+./tests/else-less-if-fail.porth:1:20: NOTE: Expected types: []
+./tests/else-less-if-fail.porth:1:20: NOTE: Actual types: [<DataType.INT: 1>]
+

tests/else-less-if.porth

@@ -0,0 +1,2 @@
+34 35 + 70 = if 69 print end
+34 35 + 69 = if 69 print end

tests/else-less-if.txt

@@ -0,0 +1,9 @@
+:i argc 0
+:b stdin 0
+
+:i returncode 0
+:b stdout 3
+69
+
+:b stderr 0
+

tests/if-else-fail.porth

@@ -0,0 +1 @@
+34 35 + 69 = if 69 print else 420 end

tests/if-else-fail.txt

@@ -0,0 +1,11 @@
+:i argc 0
+:b stdin 0
+
+:i returncode 1
+:b stdout 0
+
+:b stderr 264
+./tests/if-else-fail.porth:1:35: ERROR: both branches of the if-block must produce the same types of the arguments on the data stack
+./tests/if-else-fail.porth:1:35: NOTE: Expected types: []
+./tests/if-else-fail.porth:1:35: NOTE: Actual types: [<DataType.INT: 1>]
+

tests/if-else.porth

@@ -0,0 +1,2 @@
+34 35 + 70 = if 69 else 420 end print
+34 35 + 69 = if 69 else 420 end print

tests/if-else.txt

@@ -0,0 +1,10 @@
+:i argc 0
+:b stdin 0
+
+:i returncode 0
+:b stdout 7
+420
+69
+
+:b stderr 0
+