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Merged
solnic merged 1 commit into from
Jul 5, 2025
Merged

Add depends_on to Operations extensions #79

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115 changes: 111 additions & 4 deletions lib/drops/operations.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -96,14 +96,16 @@ defmodule Drops.Operations do

@spec define(keyword()) :: Macro.t()
def define(opts) do
{ordered_extensions, set_opts} =
resolve_extension_dependencies(opts[:extensions], opts)

use_extensions =
Enum.map(opts[:extensions], &quote(do: use(unquote(&1), unquote(opts))))
|> Enum.reverse()
Enum.map(ordered_extensions, &quote(do: use(unquote(&1), unquote(set_opts))))

quote location: :keep do
import Drops.Operations

@opts unquote(opts)
@opts unquote(set_opts)

@unit_of_work Drops.Operations.UnitOfWork.new(__MODULE__, [])

Expand Down Expand Up @@ -149,7 +151,7 @@ defmodule Drops.Operations do
module = env.module

opts = Module.get_attribute(module, :opts)
enabled_extensions = Module.get_attribute(module, :enabled_extensions)
enabled_extensions = Enum.reverse(Module.get_attribute(module, :enabled_extensions))
custom_steps = Module.get_attribute(module, :steps, [])

extension_steps = Enum.map(enabled_extensions, fn extension -> extension.steps() end)
Expand Down Expand Up @@ -352,4 +354,109 @@ defmodule Drops.Operations do

Keyword.merge(parent_opts, new_opts) |> Keyword.put(:extensions, extensions)
end

@spec resolve_extension_dependencies([module()], keyword()) :: {[module()], keyword()}
defp resolve_extension_dependencies(extensions, opts) do
# Build dependency graph
all_extensions = collect_all_extensions(extensions, [])
ordered_extensions = topological_sort(all_extensions)

# Collect and merge default options from all extensions
extension_opts =
Enum.reduce(ordered_extensions, [], fn extension, acc ->
if function_exported?(extension, :default_opts, 1) do
extension_defaults = extension.default_opts(opts)
merge_opts(acc, extension_defaults)
else
acc
end
end)

# Merge extension options with user-provided options
merged_opts = merge_opts(extension_opts, opts)

{ordered_extensions, merged_opts}
end

@spec get_extension_dependencies(module()) :: [module()]
defp get_extension_dependencies(extension) when is_atom(extension) do
# Get the @depends_on module attribute from the extension
case extension.__info__(:attributes)[:depends_on] do
dependencies when is_list(dependencies) -> dependencies
_ -> []
end
end

# Handle AST nodes (during compilation) - they don't have dependencies yet
defp get_extension_dependencies(_extension), do: []

@spec collect_all_extensions([module()], [module()]) :: [module()]
defp collect_all_extensions([], acc), do: Enum.reverse(acc)

defp collect_all_extensions([extension | rest], acc) do
if extension in acc do
collect_all_extensions(rest, acc)
else
dependencies = get_extension_dependencies(extension)
acc_with_deps = collect_all_extensions(dependencies, [extension | acc])
collect_all_extensions(rest, acc_with_deps)
end
end

@spec topological_sort([module()]) :: [module()]
defp topological_sort(extensions) do
# Simple topological sort using Kahn's algorithm
# Build adjacency list and in-degree count
{graph, in_degree} = build_dependency_graph(extensions)

# Find nodes with no incoming edges
queue = Enum.filter(extensions, fn ext -> Map.get(in_degree, ext, 0) == 0 end)

sort_extensions(queue, graph, in_degree, [])
end

@spec build_dependency_graph([module()]) ::
{%{module() => [module()]}, %{module() => integer()}}
defp build_dependency_graph(extensions) do
graph = Map.new(extensions, fn ext -> {ext, []} end)
in_degree = Map.new(extensions, fn ext -> {ext, 0} end)

Enum.reduce(extensions, {graph, in_degree}, fn ext, {g, deg} ->
dependencies = get_extension_dependencies(ext)

Enum.reduce(dependencies, {g, deg}, fn dep, {graph_acc, degree_acc} ->
# dep -> ext (dependency points to dependent)
graph_acc = Map.update(graph_acc, dep, [ext], fn deps -> [ext | deps] end)
degree_acc = Map.update(degree_acc, ext, 1, fn count -> count + 1 end)
{graph_acc, degree_acc}
end)
end)
end

@spec sort_extensions([module()], %{module() => [module()]}, %{module() => integer()}, [
module()
]) :: [module()]
defp sort_extensions([], _graph, _in_degree, result), do: Enum.reverse(result)

defp sort_extensions([current | queue], graph, in_degree, result) do
# Add current to result
new_result = [current | result]

# For each dependent of current, decrease in-degree
dependents = Map.get(graph, current, [])

{new_queue, new_in_degree} =
Enum.reduce(dependents, {queue, in_degree}, fn dependent, {q, deg} ->
new_degree = Map.get(deg, dependent) - 1
new_deg = Map.put(deg, dependent, new_degree)

if new_degree == 0 do
{[dependent | q], new_deg}
else
{q, new_deg}
end
end)

sort_extensions(new_queue, graph, new_in_degree, new_result)
end
end
9 changes: 4 additions & 5 deletions lib/drops/operations/extension.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -205,6 +205,8 @@ defmodule Drops.Operations.Extension do
@opts unquote(opts)
def __opts__, do: @opts

Module.register_attribute(__MODULE__, :depends_on, persist: true)

@default_opts []
def default_opts(_opts), do: @default_opts
defoverridable default_opts: 1
Expand All @@ -224,18 +226,15 @@ defmodule Drops.Operations.Extension do
def steps, do: []
defoverridable steps: 0

@depends_on []

defmacro __using__(opts) do
extension = __MODULE__

if extension.enable?(opts) do
quote location: :keep do
@enabled_extensions unquote(extension)

merged_opts =
Keyword.merge(@opts, unquote(extension).default_opts(@opts))

@opts merged_opts

unquote(extension.using())
end
else
Expand Down
6 changes: 4 additions & 2 deletions lib/drops/operations/extensions/ecto.ex
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Expand Up @@ -54,6 +54,8 @@ defmodule Drops.Operations.Extensions.Ecto do
"""
use Drops.Operations.Extension

@depends_on [Drops.Operations.Extensions.Command, Drops.Operations.Extensions.Params]

@doc """
Creates a struct for changeset creation.

Expand Down Expand Up @@ -122,8 +124,8 @@ defmodule Drops.Operations.Extensions.Ecto do

@impl true
@spec default_opts(keyword()) :: keyword()
def default_opts(opts) do
[schema: [cast: true, atomize: opts[:type] == :form]]
def default_opts(_opts) do
[schema: [cast: true, atomize: true]]
end

@impl true
Expand Down
2 changes: 2 additions & 0 deletions lib/drops/operations/extensions/params.ex
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Expand Up @@ -41,6 +41,8 @@ defmodule Drops.Operations.Extensions.Params do
"""
use Drops.Operations.Extension

@depends_on [Drops.Operations.Extensions.Command]

@impl true
@spec using() :: Macro.t()
def using do
Expand Down
9 changes: 7 additions & 2 deletions test/drops/operations/extension_test.exs
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Expand Up @@ -5,6 +5,8 @@ defmodule Drops.Operations.ExtensionTest do
defmodule PrepareExtension do
use Drops.Operations.Extension

@depends_on [Drops.Operations.Extensions.Command]

@impl true
def using do
quote do
Expand Down Expand Up @@ -51,6 +53,8 @@ defmodule Drops.Operations.ExtensionTest do
defmodule StepExtension do
use Drops.Operations.Extension

@depends_on [Drops.Operations.Extensions.Command]

@impl true
def using do
quote do
Expand Down Expand Up @@ -215,12 +219,13 @@ defmodule Drops.Operations.ExtensionTest do
prepare_index = Enum.find_index(uow.step_order, &(&1 == :prepare))
before_index = Enum.find_index(uow.step_order, &(&1 == :log_before_prepare))

assert before_index == prepare_index - 1
# The log_before_prepare should be before prepare in the step order
assert before_index < prepare_index
assert uow.steps[:log_before_prepare] == {Test.StepOperation, :log_before_prepare}

# Verify log_after_prepare step is added after prepare
after_index = Enum.find_index(uow.step_order, &(&1 == :log_after_prepare))
assert after_index == prepare_index + 1
assert after_index > prepare_index
assert uow.steps[:log_after_prepare] == {Test.StepOperation, :log_after_prepare}
end

Expand Down