Repository navigation
Allow Fn::If and nested Fn::Select as the Fn::Select index - #4793
Merged
kddejong merged 1 commit intoOct 21, 2026
Merged
Conversation
kddejong
approved these changes
Oct 21, 2026
The index position (prefixItems[0]) in select.json only whitelisted Ref and Fn::FindInMap (plus Fn::Length under AWS::LanguageExtensions), so E1017 reported Fn::If or a nested Fn::Select in the index slot as "is not of type 'integer'". CloudFormation accepts both: they resolve to an integer at deploy time. Add Fn::If and Fn::Select to the index function lists in both the then and else branches, and add regression tests covering each branch. Fixes aws-cloudformation#4776 Signed-off-by: Varshith Puli <pulivarshit@gmail.com>
kddejong
force-pushed
the
fix-4776-select-index-fns
branch
from
October 21, 2026 17:02
326805b to
ba2b6a9
Compare
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #4793 +/- ##
=======================================
Coverage 94.72% 94.72%
=======================================
Files 439 439
Lines 15908 15908
Branches 3079 3079
=======================================
Hits 15069 15069
Misses 458 458
Partials 381 381
Flags with carried forward coverage won't be shown. Click here to find out more. ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
|
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #4776
The
Fn::Selectindex slot (prefixItems[0]) inselect.jsonwhitelisted onlyRefandFn::FindInMap(plusFn::LengthunderAWS::LanguageExtensions), so E1017 reportedFn::Ifor a nestedFn::Selectin the index position as "is not of type 'integer'". CloudFormation accepts both shapes: they resolve to an integer at deploy time, and stacks using them reachCREATE_COMPLETE.This change adds
Fn::IfandFn::Selectto the indexcfnContext.functionslists in both thethenandelsebranches of the schema.Verification:
{'Fn::If': ['IsSet', '1', '0']} is not of type 'integer'), confirmed it is gone after the change.test_select.py(else branch) andtest_select_language_extension.py(then branch): they fail before the fix and pass after.