tarantool / go-config / 30360773524

87%

push

github

jsonschema: schema-aware scalar coercion

Environment-variable collectors deliver every value as a string, so a
strict scalar schema such as {"type": "boolean"} rejects an override like
MYAPP_FLAG=true even though the typed decode would accept it. Consumers
had to widen every env-overridable scalar to a ["boolean", "string"]
union to work around this.

Add coerceScalars, a sibling of coerceNulls, that walks the validation
data alongside the schema and parses a string into the scalar type the
schema demands (boolean, integer or number), resolving $ref and
combinators via the existing helpers. A string is coerced only when the
schema does not also permit "string" and only when it parses; an
unparseable string is left unchanged so validation still reports a type
error. Like null coercion it rewrites the validation copy only, never the
config tree, whose decode already handles string scalars.

Wire it into Validator.Validate after null coercion and cover it with
tests for the bool string forms, integer/number strings, unparseable
strings, genuine string fields, unions, and nested/array locations.

40 of 40 new or added lines in 2 files covered. (100.0%)

4061 of 4654 relevant lines covered (87.26%)

94.52 hits per line