aconfig: require exactly one bug field

Some consumers of `aconfig dump` do not support multiple bugs. At the
same time, we want all flags to be associated with at least one bug.

Teach aconfig to require that the bug field in the flag_declaration and
parsed_flag proto messages appear exactly once.

This change could have been implemented as a change of `repeated` to
`optional` in the proto definition. However, the chosen approach, with a
runtime check, is easier to revert if we want to support multiple bugs
in the future.

Bug: 293156797
Test: m all_aconfig_declarations && printflags
Test: atest aconfig.test aconfig.test.java aconfig.test.cpp
Change-Id: Ib87dac68b392986a8daa64e56cd85477c92fbe83

tools/aconfig/src/protos.rs

@@ -92,8 +92,7 @@ pub mod flag_declaration {
         ensure!(codegen::is_valid_name_ident(pdf.name()), "bad flag declaration: bad name");
         ensure!(codegen::is_valid_name_ident(pdf.namespace()), "bad flag declaration: bad name");
         ensure!(!pdf.description().is_empty(), "bad flag declaration: empty description");
-
-        // ProtoFlagDeclaration.bug: Vec<String>: may be empty, no checks needed
+        ensure!(pdf.bug.len() == 1, "bad flag declaration: exactly one bug required");
 
         Ok(())
     }
@@ -195,8 +194,7 @@ pub mod parsed_flag {
         for tp in pf.trace.iter() {
             super::tracepoint::verify_fields(tp)?;
         }
-
-        // ProtoParsedFlag.bug: Vec<String>: may be empty, no checks needed
+        ensure!(pf.bug.len() == 1, "bad flag declaration: exactly one bug required");
 
         Ok(())
     }
@@ -279,12 +277,12 @@ flag {
     namespace: "first_ns"
     description: "This is the description of the first flag."
     bug: "123"
-    bug: "abc"
 }
 flag {
     name: "second"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: "abc"
 }
 "#,
         )
@@ -294,14 +292,12 @@ flag {
         assert_eq!(first.name(), "first");
         assert_eq!(first.namespace(), "first_ns");
         assert_eq!(first.description(), "This is the description of the first flag.");
-        assert_eq!(first.bug.len(), 2);
-        assert_eq!(first.bug[0], "123");
-        assert_eq!(first.bug[1], "abc");
+        assert_eq!(first.bug, vec!["123"]);
         let second = flag_declarations.flag.iter().find(|pf| pf.name() == "second").unwrap();
         assert_eq!(second.name(), "second");
         assert_eq!(second.namespace(), "second_ns");
         assert_eq!(second.description(), "This is the description of the second flag.");
-        assert_eq!(second.bug.len(), 0);
+        assert_eq!(second.bug, vec!["abc"]);
 
         // bad input: missing package in flag declarations
         let error = flag_declarations::try_from_text_proto(
@@ -376,6 +372,36 @@ flag {
         )
         .unwrap_err();
         assert!(format!("{:?}", error).contains("bad flag declaration: bad name"));
+
+        // bad input: no bug entries in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declaration: exactly one bug required"));
+
+        // bad input: multiple bug entries in flag declaration
+        let error = flag_declarations::try_from_text_proto(
+            r#"
+package: "com.foo.bar"
+flag {
+    name: "first"
+    namespace: "first_ns"
+    description: "This is the description of the first flag."
+    bug: "123"
+    bug: "abc"
+}
+"#,
+        )
+        .unwrap_err();
+        assert!(format!("{:?}", error).contains("bad flag declaration: exactly one bug required"));
     }
 
     #[test]
@@ -482,6 +508,7 @@ parsed_flag {
     name: "first"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: "SOME_BUG"
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -495,6 +522,7 @@ parsed_flag {
     name: "second"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: "SOME_BUG"
     state: ENABLED
     permission: READ_WRITE
     trace {
@@ -516,6 +544,7 @@ parsed_flag {
         assert_eq!(second.name(), "second");
         assert_eq!(second.namespace(), "second_ns");
         assert_eq!(second.description(), "This is the description of the second flag.");
+        assert_eq!(second.bug, vec!["SOME_BUG"]);
         assert_eq!(second.state(), ProtoFlagState::ENABLED);
         assert_eq!(second.permission(), ProtoFlagPermission::READ_WRITE);
         assert_eq!(2, second.trace.len());
@@ -569,6 +598,7 @@ parsed_flag {
     name: "first"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: ""
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -582,6 +612,7 @@ parsed_flag {
     name: "second"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: ""
     state: ENABLED
     permission: READ_WRITE
     trace {
@@ -604,6 +635,7 @@ parsed_flag {
     name: "bbb"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: ""
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -617,6 +649,7 @@ parsed_flag {
     name: "aaa"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: ""
     state: ENABLED
     permission: READ_WRITE
     trace {
@@ -639,6 +672,7 @@ parsed_flag {
     name: "bar"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: ""
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -652,6 +686,7 @@ parsed_flag {
     name: "bar"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: ""
     state: ENABLED
     permission: READ_WRITE
     trace {
@@ -673,6 +708,7 @@ parsed_flag {
     name: "bar"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: "b/12345678"
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -703,6 +739,7 @@ parsed_flag {
     name: "first"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: "a"
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -716,6 +753,7 @@ parsed_flag {
     name: "second"
     namespace: "second_ns"
     description: "This is the description of the second flag."
+    bug: "b"
     state: ENABLED
     permission: READ_WRITE
     trace {
@@ -733,6 +771,7 @@ parsed_flag {
     name: "first"
     namespace: "first_ns"
     description: "This is the description of the first flag."
+    bug: "a"
     state: DISABLED
     permission: READ_ONLY
     trace {
@@ -749,6 +788,7 @@ parsed_flag {
     package: "com.second"
     name: "second"
     namespace: "second_ns"
+    bug: "b"
     description: "This is the description of the second flag."
     state: ENABLED
     permission: READ_WRITE

tools/aconfig/src/test.rs

@@ -61,7 +61,6 @@ parsed_flag {
   name: "enabled_ro"
   namespace: "aconfig_test"
   description: "This flag is ENABLED + READ_ONLY"
-  bug: "789"
   bug: "abc"
   state: ENABLED
   permission: READ_ONLY
@@ -86,6 +85,7 @@ parsed_flag {
   name: "enabled_rw"
   namespace: "aconfig_test"
   description: "This flag is ENABLED + READ_WRITE"
+  bug: ""
   state: ENABLED
   permission: READ_WRITE
   trace {

tools/aconfig/tests/test.aconfig

@@ -8,7 +8,6 @@ flag {
     name: "enabled_ro"
     namespace: "aconfig_test"
     description: "This flag is ENABLED + READ_ONLY"
-    bug: "789"
     bug: "abc"
 }
 
@@ -19,7 +18,8 @@ flag {
     name: "enabled_rw"
     namespace: "aconfig_test"
     description: "This flag is ENABLED + READ_WRITE"
-    # no bug field: bug is not mandatory
+    # for bug fields, the empty string is a discouraged but valid value
+    bug: ""
 }
 
 # This flag's final value is calculated from: