Ensure typed variables with no value still carry type#3464
Merged
crazy-max merged 1 commit intodocker:masterfrom Oct 17, 2025
Merged
Ensure typed variables with no value still carry type#3464crazy-max merged 1 commit intodocker:masterfrom
crazy-max merged 1 commit intodocker:masterfrom
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A value-less, untyped variable has always been converted to an empty
string. The intention was that value-less, typed variables convert to a
typed null, which was even specified in a code comment, but was never
actually implemented.
This resulted in a null value with a nil type. A value with a nil type
cannot be coerced ("unified") with any other standard types. When this
mismatch occurs, HCL attempts to return a diagnostic error, which in
turn panics as the nil type is literally a nil pointer.
Signed-off-by: Roberto Villarreal <rrjjvv@yahoo.com>
tonistiigi
approved these changes
Oct 14, 2025
crazy-max
approved these changes
Oct 17, 2025
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Fixes #3463
A value-less, untyped variable has always been converted to an empty string. The intention was that value-less, typed variables convert to a typed null, which was even specified in a code comment, but was never actually implemented.
This resulted in a null value with a nil type. A value with a nil type cannot be coerced ("unified") with any other standard types. When this mismatch occurs, HCL attempts to return a diagnostic error, which in turn panics as the nil type is literally a nil pointer.
There were existing tests that covered value-less, typed variables, but those were centered around ensuring that bake could handle them and didn't alter their value (unlike untyped variables); they treated no value (or explicit null) more as an error condition/edge case and didn't cover intentional uses.
Also, I noticed at some point some JSON-specific tests were added to complement the HCL-specific tests around typing; let me know if this PR should have equivalent JSON tests as well.