"Add missing case clauses" only inserts first case for switch pattern statements

[DanTup]

With language version 2.19 this works correctly:

But for 3.0 it only inserts one case:

This missing test might be related, though it seems to be looking for a different fix to the one being produced (perhaps it's intended for pre-3.0 code, but probably it shouldn't be failing if that's the case).

sdk/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart

Line 41 in 498dcc0

@FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/49759')

[bwilkerson]

Unfortunately, that behavior is the best we can do at the moment. With the switch to patterns we had to write a much more general algorithm to compute exhaustiveness, and that algorithm currently only finds the first case that isn't covered. There have been discussions about extending the algorithm to find all of the missing cases so that we can do a better job, but I don't know what the state of that work is.

@scheglov

[deimantasa]

Any updates to this? It feels like a serious bummer, especially when having several (5+) enum cases to deal with. Auto-fill used to save tons of time.

P.S. Android Studio (Flamingo) does not even generate one case. Only by hovering, first case is hinted.

[pq]

There have been discussions about extending the algorithm to find all of the missing cases so that we can do a better job, but I don't know what the state of that work is.

@scheglov?

[lhengl]

Just upgraded to dart 3 and stumbled into this problem. There used to be fixes available for exhaustiveness, now there isn't. With the prevalent use of enum and switch statements, I'm surprised this issue doesn't have more upvotes.

[AbdulazizRasulbek]

same issue for sealed classes

[bwilkerson]

This has been fixed by https://dart-review.googlesource.com/c/sdk/+/371062 and should be available in the next stable release.

[DanTup]

@bwilkerson I tested this and it seems to work great 🥳 but I noticed the test I linked up top is still marked @FailingTest:

sdk/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart

Line 41 in 498dcc0

@FailingTest(issue: 'https://github.com/dart-lang/sdk/issues/49759')

It fails because of "Unnecessary error filter" (a test bug), but if I remove the WithFilter, it fails with:

Expected to find fix dart.fix.add.missingEnumCaseClauses in
Fix(kind=dart.fix.add.missingSwitchCases, change={"message":"Add missing switch cases","edits":[{"file":"C:\home\test\lib\test.dart","fileStamp":0,"edits":[{"offset":49,"length":0,"replacement":" case E.a:\r\n // TODO: Handle this case.\r\n case E.b:\r\n // TODO: Handle this case.\r\n case E.c:\r\n // TODO: Handle this case.\r\n"}]}],"linkedEditGroups":[],"id":"dart.fix.add.missingSwitchCases"})

It looks like the fix provided is dart.fix.add.missingSwitchCases but this test is for dart.fix.add.missingEnumCaseClauses. It's not clear to me what the difference is here (I thought maybe one is for the original switch statement parsing and the other is since switch expressions were added, but I don't think that explains how any of other other tests in this class would be passing).

Oh, as I was about to send this I noticed all the non-failing tests in that class are marked // @dart=2.19.

So.. should all of the @FailingTests in the class AddMissingEnumCaseClausesTest now be moved into AddMissingSwitchCasesTest_SwitchStatement since it seems for >2.19 they'll all be handled by that fix instead?

[bwilkerson]

The fix kind DartFixKind.ADD_MISSING_ENUM_CASE_CLAUSES is associated with AddMissingEnumCaseClauses, which is associated with StaticWarningCode.MISSING_ENUM_CONSTANT_IN_SWITCH. That warning code is produced only in pre-pattern-enabled code.

The fix kind DartFixKind.ADD_MISSING_SWITCH_CASES is associated with AddMissingSwitchCases, which is associated with both CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_EXPRESSION and CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_STATEMENT, both of which are only produced in pattern-enabled code.

... should all of the @FailingTests in the class AddMissingEnumCaseClausesTest now be moved into AddMissingSwitchCasesTest since it seems for >2.19 they'll all be handled by that fix instead?

If the tests are intended to be run with patterns enabled, then yes, they should be moved because they will produce the CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_EXPRESSION and CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_STATEMENT diagnostics, and AddMissingSwitchCasesTest is where those tests should live.