softwaremill/magnolia

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Easy, fast, transparent generic derivation of typeclass instances

Stars: 802
Forks: 128
Open beginner issues: 0
Indexed issues: 61

Dominant language: Scala
License: Apache-2.0
Last GitHub push: Jul 14, 2026
Latest indexed: Sep 19, 2026
Contributing guide: No contributing guide
Code of conduct: No code of conduct
Beginner labels: good first issue
PR merge metrics: No merged PRs in 30d

Beginner friendly Everything

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61 open issues indexed

Support Java 25 without warnings Open

Difficulty 3/5 1-2 days Newbie friendliness 55/100

softwaremill/magnolia#671 · Opened Sep 11, 2026
unused warnings after macro expansion for sealed traits Open

Difficulty 3/5 1-2 days Newbie friendliness 64/100

softwaremill/magnolia#634 · 2 comments · Opened Mar 12, 2026
Support covariant typeclass families Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

softwaremill/magnolia#627 · 4 comments · Opened Feb 17, 2026
Consider enum cases as objects? Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

softwaremill/magnolia#598 · 3 comments · Opened May 26, 2025
Missing typeName / typeInfo for case class parameters on Scala 3 Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

softwaremill/magnolia#582 · 1 comment · Opened Feb 27, 2025
Bring the scala3-v2 branch up-to-date, review, publish Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

softwaremill/magnolia#552 · 2 comments · 2 reactions · Opened Oct 30, 2024
[question] Derivation differences between Scala 2 and 3 Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

softwaremill/magnolia#550 · 3 comments · Opened Oct 24, 2024
Does Magnolia 1 for Scala 2 support getting the original index of a subtype in a sealed trait? Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#514 · 7 comments · Opened Feb 22, 2024
Typeclass Different from the Derived type Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#510 · Opened Jan 12, 2024
Support heterogenous typeclass derivation Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

softwaremill/magnolia#503 · Opened Dec 19, 2023
typeinfo is error-prone Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#475 · Opened Jun 16, 2023
[bug] type arguments can't be determined from Any Open

bug

softwaremill/magnolia#472 · 1 assignee · Opened Jun 13, 2023
Question: Scala 3 automatic derivation Open

Difficulty 5/5 Over a week Newbie friendliness 15/100

softwaremill/magnolia#470 · 2 comments · Opened May 31, 2023
Type classes for parameter are not lazy Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#466 · 3 comments · Opened May 22, 2023
StackOverflowException for contra-variant type-class Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#464 · 1 comment · Opened Apr 10, 2023
Magnolia interface unification for Scala 2 and Scala 3 versions Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#458 · 1 comment · 4 reactions · Opened Feb 15, 2023
Possibly improve how magnolia checks that an enum is not an ADT Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

softwaremill/magnolia#456 · Opened Feb 2, 2023
"Internal error: unable to find the outer accessor symbol of ..." when deriving instance for a nested type Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#449 · 3 comments · Opened Jan 14, 2023
Add more typeclass examples and test cases. Open

good first issue warsaw-spree

Difficulty 3/5 1-2 days Newbie friendliness 45/100

softwaremill/magnolia#439 · Opened Dec 5, 2022
Recursive derivation not working Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#424 · 1 reaction · Opened Sep 12, 2022
Multiple Parameter Lists Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

softwaremill/magnolia#416 · 1 comment · Opened Aug 10, 2022
Null typeclass for Param in automatic derivation Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#402 · 2 comments · Opened May 30, 2022
Regression in recursive data types derivation Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

softwaremill/magnolia#401 · Opened May 15, 2022
macro implementations cannot have implicit parameters other than WeakTypeTag evidences Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#396 · 4 comments · 1 reaction · Opened Apr 24, 2022
method is declared as erased, but is in fact used Open

scala3

Difficulty 4/5 3-5 days Newbie friendliness 30/100

softwaremill/magnolia#374 · 2 comments · Opened Jan 24, 2022
Derivation for class with collection field Open

scala3

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#370 · 2 comments · Opened Jan 18, 2022
How to use auto-derivation with contravariant TC Open

scala3

Difficulty 4/5 3-5 days Newbie friendliness 32/100

softwaremill/magnolia#336 · 10 comments · Opened Sep 12, 2021
Is it possible to intentionally fail at compile time? Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

softwaremill/magnolia#324 · 1 comment · Opened Jul 3, 2021
Investigate how new Scala3 types can be supported Open

scala3

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#316 · 3 reactions · Opened Jun 12, 2021
Consider not using Mirrors for derivation, so that multi-level hierarchies can be suppored Open

scala3

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#310 · 4 comments · Opened Jun 10, 2021
Exclude params and cons from the derivation based on annotations Open

softwaremill/magnolia#297 · 35 comments · 1 assignee · Opened May 20, 2021
Missing features for Scala 3 Open

scala3

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#296 · 15 comments · 1 reaction · Opened May 19, 2021
Scala 3 caveats Open

Difficulty 2/5 1-3 hours Newbie friendliness 35/100

softwaremill/magnolia#294 · 1 comment · 2 reactions · Opened May 18, 2021
Better error messages Open

scala3

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#292 · 2 comments · Opened May 18, 2021
Support typeclasses for types with * -> * kind in Scala 3 Open

scala3

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#288 · Opened May 14, 2021
forward reference issue when using exported instance of contravariant type class Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#277 · Opened Dec 30, 2020
Derive a typeclass for sealed families of case objects only Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#267 · 3 comments · 1 reaction · Opened Sep 4, 2020
consider merging `ReadOnly...` APIs Open

api enhancement question

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#256 · 3 comments · 2 reactions · Opened May 17, 2020
Defining class within parent's companion object breaks magnolia implicit resolution Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

softwaremill/magnolia#252 · Opened May 11, 2020
Spurious compilation errors Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#242 · 5 comments · Opened May 4, 2020
Support @implicitNotFound errors Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 25/100

softwaremill/magnolia#239 · 3 comments · Opened Apr 21, 2020
Wish list: Support inlined dispatch/combine calls Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#238 · 5 comments · Opened Apr 21, 2020
Intermittent runtime StackOverflowError with multi-level sealed hierarchy Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#216 · 15 comments · Opened Mar 25, 2020
Best way to deal with ambiguous implicit values with other libraries w.r.t. List, Option, etc? Open

question

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#213 · 4 comments · Opened Mar 10, 2020
Given a sealed trait, expose all of its case class subtypes's names in ctx in dispatch function Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

softwaremill/magnolia#172 · 6 comments · Opened Jul 22, 2019
@transient not picked up in annotatations array Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

softwaremill/magnolia#163 · 1 comment · Opened May 16, 2019
Example with `default` doesn't compile for me Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

softwaremill/magnolia#144 · 4 comments · Opened Nov 20, 2018
Accumulate errors for all missing implicits Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#140 · 10 comments · Opened Sep 23, 2018
Classes with a companion object and private constructor are not supported Open

Difficulty 4/5 3-5 days Newbie friendliness 40/100

softwaremill/magnolia#138 · 2 comments · 1 reaction · Opened Sep 3, 2018
Support Java enums Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 35/100

softwaremill/magnolia#137 · 1 comment · Opened Aug 29, 2018

softwaremill/magnolia

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