Merge pull request #605 from conjure-cp/fix-521

Adding a regression test case for #521

tests/custom/issues/521/1.essence

@@ -0,0 +1,2 @@
+find b : bool
+such that b = ([1, 2, 3] = flatten([1, 2, 3], 0))

tests/custom/issues/521/2.essence

@@ -0,0 +1,2 @@
+find c : bool
+such that c = alldifferent_except([1, 2, 5, 1, 6])

tests/custom/issues/521/3.essence

@@ -0,0 +1,2 @@
+find b : set of int(1..6)
+such that b = party(5)

tests/custom/issues/521/run.sh

@@ -0,0 +1,5 @@
+rm -rf conjure-output
+conjure solve 1.essence
+conjure solve 2.essence
+conjure solve 3.essence
+rm -rf conjure-output

tests/custom/issues/521/stderr.expected

@@ -0,0 +1,28 @@
+Error:
+    1.essence:2:36:
+  |
+2 | such that b = ([1, 2, 3] = flatten([1, 2, 3], 0))
+  |                                    ^^^^^^^^^
+Error: 1st arg must be a constant positive int
+
+1.essence:2:47:
+  |
+2 | such that b = ([1, 2, 3] = flatten([1, 2, 3], 0))
+  |                                               ^
+Type error:
+	Expected: [[?]]
+	Got: int
+
+Error:
+    2.essence:2:34:
+  |
+2 | such that c = alldifferent_except([1, 2, 5, 1, 6])
+  |                                  ^^^^^^^^^^^^^^^^^
+Insufficient args, expected 2 got 1
+
+Error: 3.essence:2:20:
+  |
+2 | such that b = party(5)
+  |                    ^^^
+Insufficient args, expected 2 got 1
+