tests/basics: Add initial tests for := operator.

dpgeorge · dpgeorge · commit c3560e085ba7 · 2020-06-11T11:00:00.000+10:00
diff --git a/tests/basics/assign_expr.py b/tests/basics/assign_expr.py
@@ -0,0 +1,46 @@
+(x := 4)
+print(x)
+
+if x := 2:
+    print(True)
+print(x)
+
+print(min(4, x := 5))
+print(x)
+
+x = 1
+print(min(x, x := 5))
+print(x)
+
+
+def foo():
+    print("any", any((hit := i) % 5 == 3 and (hit % 2) == 0 for i in range(10)))
+    return hit
+
+
+hit = 123
+print(foo())
+print(hit)  # shouldn't be changed by foo
+
+print("any", any((hit := i) % 5 == 3 and (hit % 2) == 0 for i in range(10)))
+print(hit)  # should be changed by above
+
+print([i := i + 1 for i in range(4)])
+print(i)
+del i
+
+print([i := -1 for i, j in [(1, 2)]])
+print(i)
+
+print([((m := k + 1), k * m) for k in range(4)])
+
+# j doesn't exist
+try:
+    print([[(j := j) for i in range(2)] for j in range(2)])
+except NameError:
+    print("NameError")
+
+# j is a global
+j = 9
+print([[(j := j) for i in range(2)] for j in range(2)])
+print(j)
diff --git a/tests/basics/assign_expr.py.exp b/tests/basics/assign_expr.py.exp
@@ -0,0 +1,20 @@
+4
+True
+2
+4
+5
+1
+5
+any True
+8
+123
+any True
+8
+[1, 2, 3, 4]
+4
+[-1]
+-1
+[(1, 0), (2, 2), (3, 6), (4, 12)]
+NameError
+[[9, 9], [9, 9]]
+9
