Improve error message for 'missing-return-value' check.

RELNOTES: None.
PiperOrigin-RevId: 176899549

2 files changed, 5 insertions, 0 deletions

diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
index b7f94e9516..db28c52f6d 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
@@ -166,6 +166,7 @@ public class ControlFlowChecker extends SyntaxTreeVisitor {
               "some but not all execution paths of '"
                   + node.getIdentifier()
                   + "' return a value."
+                  + " If it is intentional, make it explicit using 'return None'."
                   + " If you know these cannot happen,"
                   + " add the statement `fail('unreachable')` to them."
                   + " For more details, have a look at the documentation.",
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
index 16099a7184..6d7a673acc 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
@@ -53,6 +53,7 @@ public class ControlFlowCheckerTest {
                 .toString())
         .contains(
             "1:1-5:12: some but not all execution paths of 'some_function' return a value."
+                + " If it is intentional, make it explicit using 'return None'."
                 + " If you know these cannot happen,"
                 + " add the statement `fail('unreachable')` to them."
                 + " For more details, have a look at the documentation. [missing-return-value]");
@@ -71,6 +72,7 @@ public class ControlFlowCheckerTest {
     Truth.assertThat(messages)
         .contains(
             "1:1-5:10: some but not all execution paths of 'some_function' return a value."
+                + " If it is intentional, make it explicit using 'return None'."
                 + " If you know these cannot happen,"
                 + " add the statement `fail('unreachable')` to them."
                 + " For more details, have a look at the documentation. [missing-return-value]");
@@ -94,6 +96,7 @@ public class ControlFlowCheckerTest {
                 .toString())
         .contains(
             "1:1-7:16: some but not all execution paths of 'f' return a value."
+                + " If it is intentional, make it explicit using 'return None'."
                 + " If you know these cannot happen,"
                 + " add the statement `fail('unreachable')` to them."
                 + " For more details, have a look at the documentation. [missing-return-value]");
@@ -114,6 +117,7 @@ public class ControlFlowCheckerTest {
                 .toString())
         .contains(
             "1:1-8:12: some but not all execution paths of 'f' return a value."
+                + " If it is intentional, make it explicit using 'return None'."
                 + " If you know these cannot happen,"
                 + " add the statement `fail('unreachable')` to them."
                 + " For more details, have a look at the documentation. [missing-return-value]");