Augmented assignments don't evaluate lhs multiple times
--
PiperOrigin-RevId: 148092963
MOS_MIGRATED_REVID=148092963
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index 0a701e0..6353c12 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -909,6 +909,49 @@
}
@Test
+ public void testAugmentedAssignmentHasNoSideEffects() throws Exception {
+ new SkylarkTest().setUp(
+ "counter = [0]",
+ "value = [1, 2]",
+ "",
+ "def f():",
+ " counter[0] = counter[0] + 1",
+ " return value",
+ "",
+ "f()[1] += 1") // `f()` should be called only once here
+ .testLookup("counter", MutableList.of(env, 1));
+ }
+
+ @Test
+ public void testAugmentedAssignmentNotAllowedForListLiterals() throws Exception {
+ new SkylarkTest().testIfErrorContains("Cannot perform augment assignment on a list literal",
+ "def f(a, b):",
+ " [a, b] += []",
+ "f(1, 2)");
+ }
+
+ @Test
+ public void testAssignmentEvaluationOrder() throws Exception {
+ new SkylarkTest().setUp(
+ "ordinary = []",
+ "augmented = []",
+ "value = [1, 2]",
+ "",
+ "def f(record):",
+ " record.append('f')",
+ " return value",
+ "",
+ "def g(record):",
+ " record.append('g')",
+ " return value",
+ "",
+ "f(ordinary)[0] = g(ordinary)[1]",
+ "f(augmented)[0] += g(augmented)[1]")
+ .testLookup("ordinary", MutableList.of(env, "g", "f")) // This order is consistent
+ .testLookup("augmented", MutableList.of(env, "f", "g")); // with Python
+ }
+
+ @Test
public void testStaticDirectJavaCall() throws Exception {
new SkylarkTest().update("Mock", Mock.class).setUp("val = Mock.value_of('8')")
.testLookup("val", 8);
