v0.9.0

The planning behind produce, pre_produce, exec and pre_exec was rebuilt.

What you can rely on

• After produce, every requested entity is in the context, with every requested trait. A request that cannot be honoured fails before anything runs. Previously such a request could return a context silently missing the entity or the trait, or crash halfway through the execution.
• Plans that need an alternative are found: another command producing the entity, another route to a trait, a command re-producing an entity after a deleting command consumed it. Previously these requests failed with a false circular-dependency or trait error.
• Entities already in the context are respected: a command re-producing one needs a deleting command in between, and the commands consuming, deleting and re-producing it run in a valid order. Previously that order could depend on command names and crash or hand a command an entity in the wrong state.
• A command runs only once the entities its params name exist and carry the traits their with_traits ask for at that moment. Previously a planned command could receive an entity a later-planned command had already stripped of the trait, or one it had deleted.
• A request is a set: the plan does not depend on the order of its entries or of the traits within an entry. Previously the entity named first could pick a producer the others then had to live with, and the same request written in another order produced different side entities and traits.
• pre_produce prepares the dependencies of the requested entities even when producing everything in one produce call would be impossible, and never consumes an entity the request names.

What changed for schemas

• The generate functions of params and the generate_args functions of trait declarations run once, while the plan is built and before any command executes; the execution reuses the values. Keep them to producing values (random data, counters), without writes to a database or a file.
• A trait declared with from replaces the named trait, and a command that later asks for the replaced trait through with_traits is refused, where it used to run. A trait that adds a property without leaving the previous state is declared without from.

Requirements

• Elixir 1.19 or later. The previous minimum was 1.15.

Errors

A refused request explains every candidate it rejected:

cannot produce entity :contract: no candidate command fits the plan
- :sign_contract would duplicate existing :contract_copy (rebind or delete it first)
- :import_contract would duplicate existing :approval (rebind or delete it first)

A plan that would end without a requested trait raises SeedFactory.MissingRequestedTraitError, naming the command whose transition removes the trait.

SeedFactory.ConflictingTraitsError is gone. Two requested traits whose commands would both produce the same entity are refused with the reason also produces :x, already produced by :y in this plan. A request one command can serve on its own now succeeds, where the removed check refused it.

A request asking for a trait together with one that replaces it is refused naming the request. The message used to name a nil command.

Bug fixes

• A requested trait consumed by a transition declared with a from list was silently skipped. It now raises, like a transition declared with a single from.
• with_traits on an entity param accepted an entity that had gone through the required trait and lost it. It now raises, or uses another candidate when one exists.
• Trait resolution gave up when the first option of a from list could not be satisfied. The options are now tried in the declared order.
• A trait declared on several commands was reported as a mismatch when one executed command did not add it while another did. Every executed declaration is now reported.
• Input for a param nested in a param ... do ... end container did not cover the dependency: the command producing it still ran.
• The compile-time trait cycle check missed a cycle through a from edge of a shadowed declaration. Such a schema compiled and could hang produce.