TruncateTransform.satisfies_order_of raises AttributeError for different widths

Start in pyiceberg/transforms.py at TruncateTransform.satisfies_order_of and review the related constructor and source_type property. Run the focused cases in tests/test_transforms.py around lines 501-512, then add coverage for different widths. Done means comparisons return the expected booleans without accessing an uninitialized attribute.

Apache Iceberg version

0.11.0 (latest release)

Please describe the bug 🐞

Description

Calling TruncateTransform.satisfies_order_of with two valid truncate transforms that have different widths raises an AttributeError instead of returning a boolean.

Same-width comparisons work because the method returns early when the transforms are equal.

Reproduction

from pyiceberg.transforms import TruncateTransform

TruncateTransform(5).satisfies_order_of(TruncateTransform(3))

On main at commit 48e710d20ceeeaa637d5aeae7746b787410859f8, this raises:

AttributeError: 'TruncateTransform' object has no attribute '_source_type'

The failure reproduces consistently. The same code is also present in the 0.11.1 release.

Expected behavior

The method should compare the truncate widths and return a boolean:

assert TruncateTransform(5).satisfies_order_of(TruncateTransform(3))
assert not TruncateTransform(3).satisfies_order_of(TruncateTransform(5))

This matches the current Apache Iceberg Java implementation:

https://github.com/apache/iceberg/blob/25654ab4b29c8b5b5c20fc427da01cb70d94ed14/api/src/main/java/org/apache/iceberg/transforms/Truncate.java#L130-L141

Cause

TruncateTransform.__init__ initializes _width but not _source_type. However, satisfies_order_of still accesses the source_type property backed by _source_type:

https://github.com/apache/iceberg-python/blob/48e710d20ceeeaa637d5aeae7746b787410859f8/pyiceberg/transforms.py#L783-L905

The existing unit test only compares a transform with itself, so it returns before reaching the failing branch:

https://github.com/apache/iceberg-python/blob/48e710d20ceeeaa637d5aeae7746b787410859f8/tests/test_transforms.py#L501-L512

A focused fix could compare TruncateTransform widths directly, consistent with the Java implementation, and add regression cases for different widths.

I would be happy to contribute the fix and regression tests.

Willingness to contribute

• I can contribute a fix for this bug independently
• I would be willing to contribute a fix for this bug with guidance from the Iceberg community
• I cannot contribute a fix for this bug at this time