Accept empty string as null in PluginModel deserializer and add Coerc…#6915
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Davidding4718 wants to merge 3 commits into
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Accept empty string as null in PluginModel deserializer and add Coerc…#6915Davidding4718 wants to merge 3 commits into
Davidding4718 wants to merge 3 commits into
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…ionConfig for settings conversion Signed-off-by: Siqi Ding <dingdd@amazon.com>
Davidding4718
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KarstenSchnitter,
Zhangxunmt,
dinujoh,
divbok,
dlvenable,
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kkondaka,
oeyh,
san81,
sb2k16,
srikanthjg and
srikanthpadakanti
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dlvenable
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Jun 11, 2026
| private static final ObjectMapper SERIALIZER_OBJECT_MAPPER = new ObjectMapper(); | ||
| static { | ||
| SERIALIZER_OBJECT_MAPPER.coercionConfigDefaults() | ||
| .setCoercion(CoercionInputShape.EmptyString, CoercionAction.AsNull); |
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I'm not sure this is the right solution. It is going to affect all strings making them the same as null.
I think we should avoid this coercion.
In the plugin framework we handle the situation where the plugin is provided as:
something_using_a_plugin:
some_plugin: ""
Only when parsing the PluginModel should you treat an empty string ("") the same as null.
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You're right. The global CoercionConfig was too broad and would silently null out legitimate empty strings in plugin settings. I have removed it in the newest commit.
Remove the SERIALIZER_OBJECT_MAPPER CoercionConfig that globally coerced empty strings to null across all fields. The targeted VALUE_STRING check in the deserializer already handles bare YAML keys (e.g. stdout:) by treating empty string as null only at the plugin name level. Signed-off-by: Siqi Ding <dingdd@amazon.com>
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Jun 16, 2026
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Thanks @Davidding4718 for the contribution!
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Description
After Jackson-dataformat-yaml 2.13+, bare YAML keys (e.g.,
stdout:,newline:) produceVALUE_STRING ""instead ofVALUE_NULL. This change updates PluginModel to:stdout:are treated as plugins with null settings (same behavior as Jackson 2.12)EmptyString → AsNullso that when plugin settings are converted to typed model classes viaconvertValue(), empty strings from bare YAML keys are coerced to nullThis maintains backward compatibility for pipeline configurations that use bare keys for plugins with no settings, which is the standard YAML pattern for Data Prepper pipelines.
Issues Resolved
Resolves #6598 (follow-up — original PR rejected empty strings; this accepts them per team decision)
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