stacklok / toolhive / 21485790118

60%

Build Type

push

github

Committed by web-flow

Commit Message

fix(vmcp) - template validation with functions (#3492)

While I was working on stacklok/docs-website#367, I attempted to validate the documented composite tool which used the fromJson function. However, the ValidateTemplate function in composite_validation.go was parsing templates without registering the custom template functions available at runtime. This caused validation to reject valid templates with errors like:

function "fromJson" not defined
This PR fixes template validation failing for composite tools that use custom template functions like fromJson, json, and quote.

Solution: Consolidate template function definitions into a shared FuncMap() in pkg/templates/funcs.go. Both validation and runtime now import from this single source of truth, ensuring parity between what validates and what executes.


Changes
In commit 1:

Add e2e test that verifies VirtualMCPServer with fromJson templates becomes ready. This fails without the following commit.
In commit 2:

Add pkg/templates/funcs.go with shared FuncMap() containing json, quote, and fromJson
Update pkg/vmcp/composer/template_expander.go to use templates.FuncMap()
Update pkg/vmcp/config/composite_validation.go to use templates.FuncMap() in ValidateTemplate
Update pkg/templates/references.go to use FuncMap() in ExtractReferences

Run Details

23 of 25 new or added lines in 4 files covered. (92.0%)

33 existing lines in 3 files now uncovered.

39209 of 64874 relevant lines covered (60.44%)

77.02 hits per line