bundler/lib/bundler/resolver.rb
# frozen_string_literal: true
module Bundler
#
# This class implements the interface needed by PubGrub for resolution. It is
# equivalent to the `PubGrub::BasicPackageSource` class provided by PubGrub by
# default and used by the most simple PubGrub consumers.
#
class Resolver
require_relative "vendored_pub_grub"
require_relative "resolver/base"
require_relative "resolver/candidate"
require_relative "resolver/incompatibility"
require_relative "resolver/root"
include GemHelpers
def initialize(base, gem_version_promoter)
@source_requirements = base.source_requirements
@base = base
@gem_version_promoter = gem_version_promoter
end
def start
@requirements = @base.requirements
@packages = @base.packages
root, logger = setup_solver
Bundler.ui.info "Resolving dependencies...", true
solve_versions(root: root, logger: logger)
end
def setup_solver
root = Resolver::Root.new(name_for_explicit_dependency_source)
root_version = Resolver::Candidate.new(0)
@all_specs = Hash.new do |specs, name|
source = source_for(name)
matches = source.specs.search(name)
# Don't bother to check for circular deps when no dependency API are
# available, since it's too slow to be usable. That edge case won't work
# but resolution other than that should work fine and reasonably fast.
if source.respond_to?(:dependency_api_available?) && source.dependency_api_available?
matches = filter_invalid_self_dependencies(matches, name)
end
specs[name] = matches.sort_by {|s| [s.version, s.platform.to_s] }
end
@all_versions = Hash.new do |candidates, package|
candidates[package] = all_versions_for(package)
end
@sorted_versions = Hash.new do |candidates, package|
candidates[package] = filtered_versions_for(package).sort
end
@sorted_versions[root] = [root_version]
root_dependencies = prepare_dependencies(@requirements, @packages)
@cached_dependencies = Hash.new do |dependencies, package|
dependencies[package] = Hash.new do |versions, version|
versions[version] = to_dependency_hash(version.dependencies.reject {|d| d.name == package.name }, @packages)
end
end
@cached_dependencies[root] = { root_version => root_dependencies }
logger = Bundler::UI::Shell.new
logger.level = debug? ? "debug" : "warn"
[root, logger]
end
def solve_versions(root:, logger:)
solver = PubGrub::VersionSolver.new(source: self, root: root, logger: logger)
result = solver.solve
result.map {|package, version| version.to_specs(package) }.flatten.uniq
rescue PubGrub::SolveFailure => e
incompatibility = e.incompatibility
names_to_unlock, names_to_allow_prereleases_for, extended_explanation = find_names_to_relax(incompatibility)
names_to_relax = names_to_unlock + names_to_allow_prereleases_for
if names_to_relax.any?
if names_to_unlock.any?
Bundler.ui.debug "Found conflicts with locked dependencies. Will retry with #{names_to_unlock.join(", ")} unlocked...", true
@base.unlock_names(names_to_unlock)
end
if names_to_allow_prereleases_for.any?
Bundler.ui.debug "Found conflicts with dependencies with prereleases. Will retrying considering prereleases for #{names_to_allow_prereleases_for.join(", ")}...", true
@base.include_prereleases(names_to_allow_prereleases_for)
end
root, logger = setup_solver
Bundler.ui.debug "Retrying resolution...", true
retry
end
explanation = e.message
if extended_explanation
explanation << "\n\n"
explanation << extended_explanation
end
raise SolveFailure.new(explanation)
end
def find_names_to_relax(incompatibility)
names_to_unlock = []
names_to_allow_prereleases_for = []
extended_explanation = nil
while incompatibility.conflict?
cause = incompatibility.cause
incompatibility = cause.incompatibility
incompatibility.terms.each do |term|
package = term.package
name = package.name
if base_requirements[name]
names_to_unlock << name
elsif package.ignores_prereleases? && @all_specs[name].any? {|s| s.version.prerelease? }
names_to_allow_prereleases_for << name
end
no_versions_incompat = [cause.incompatibility, cause.satisfier].find {|incompat| incompat.cause.is_a?(PubGrub::Incompatibility::NoVersions) }
next unless no_versions_incompat
extended_explanation = no_versions_incompat.extended_explanation
end
end
[names_to_unlock.uniq, names_to_allow_prereleases_for.uniq, extended_explanation]
end
def parse_dependency(package, dependency)
range = if repository_for(package).is_a?(Source::Gemspec)
PubGrub::VersionRange.any
else
requirement_to_range(dependency)
end
PubGrub::VersionConstraint.new(package, range: range)
end
def versions_for(package, range=VersionRange.any)
versions = select_sorted_versions(package, range)
# Conditional avoids (among other things) calling
# sort_versions_by_preferred with the root package
if versions.size > 1
sort_versions_by_preferred(package, versions)
else
versions
end
end
def no_versions_incompatibility_for(package, unsatisfied_term)
cause = PubGrub::Incompatibility::NoVersions.new(unsatisfied_term)
name = package.name
constraint = unsatisfied_term.constraint
constraint_string = constraint.constraint_string
requirements = constraint_string.split(" OR ").map {|req| Gem::Requirement.new(req.split(",")) }
if name == "bundler" && bundler_pinned_to_current_version?
custom_explanation = "the current Bundler version (#{Bundler::VERSION}) does not satisfy #{constraint}"
extended_explanation = bundler_not_found_message(requirements)
else
specs_matching_other_platforms = filter_matching_specs(@all_specs[name], requirements)
platforms_explanation = specs_matching_other_platforms.any? ? " for any resolution platforms (#{package.platforms.join(", ")})" : ""
custom_explanation = "#{constraint} could not be found in #{repository_for(package)}#{platforms_explanation}"
label = "#{name} (#{constraint_string})"
extended_explanation = other_specs_matching_message(specs_matching_other_platforms, label) if specs_matching_other_platforms.any?
end
Incompatibility.new([unsatisfied_term], cause: cause, custom_explanation: custom_explanation, extended_explanation: extended_explanation)
end
def debug?
ENV["BUNDLER_DEBUG_RESOLVER"] ||
ENV["BUNDLER_DEBUG_RESOLVER_TREE"] ||
ENV["DEBUG_RESOLVER"] ||
ENV["DEBUG_RESOLVER_TREE"] ||
false
end
def incompatibilities_for(package, version)
package_deps = @cached_dependencies[package]
sorted_versions = @sorted_versions[package]
package_deps[version].map do |dep_package, dep_constraint|
low = high = sorted_versions.index(version)
# find version low such that all >= low share the same dep
while low > 0 && package_deps[sorted_versions[low - 1]][dep_package] == dep_constraint
low -= 1
end
low =
if low == 0
nil
else
sorted_versions[low]
end
# find version high such that all < high share the same dep
while high < sorted_versions.length && package_deps[sorted_versions[high]][dep_package] == dep_constraint
high += 1
end
high =
if high == sorted_versions.length
nil
else
sorted_versions[high]
end
range = PubGrub::VersionRange.new(min: low, max: high, include_min: true)
self_constraint = PubGrub::VersionConstraint.new(package, range: range)
dep_term = PubGrub::Term.new(dep_constraint, false)
self_term = PubGrub::Term.new(self_constraint, true)
custom_explanation = if dep_package.meta? && package.root?
"current #{dep_package} version is #{dep_constraint.constraint_string}"
end
PubGrub::Incompatibility.new([self_term, dep_term], cause: :dependency, custom_explanation: custom_explanation)
end
end
def all_versions_for(package)
name = package.name
results = (@base[name] + filter_prereleases(@all_specs[name], package)).uniq {|spec| [spec.version.hash, spec.platform] }
if name == "bundler" && !bundler_pinned_to_current_version?
bundler_spec = Gem.loaded_specs["bundler"]
results << bundler_spec if bundler_spec
end
locked_requirement = base_requirements[name]
results = filter_matching_specs(results, locked_requirement) if locked_requirement
results.group_by(&:version).reduce([]) do |groups, (version, specs)|
platform_specs = package.platforms.map {|platform| select_best_platform_match(specs, platform) }
# If package is a top-level dependency,
# candidate is only valid if there are matching versions for all resolution platforms.
#
# If package is not a top-level deependency,
# then it's not necessary that it has matching versions for all platforms, since it may have been introduced only as
# a dependency for a platform specific variant, so it will only need to have a valid version for that platform.
#
if package.top_level?
next groups if platform_specs.any?(&:empty?)
else
next groups if platform_specs.all?(&:empty?)
end
platform_specs.flatten!
ruby_specs = select_best_platform_match(specs, Gem::Platform::RUBY)
groups << Resolver::Candidate.new(version, specs: ruby_specs) if ruby_specs.any?
next groups if platform_specs == ruby_specs || package.force_ruby_platform?
groups << Resolver::Candidate.new(version, specs: platform_specs)
groups
end
end
def source_for(name)
@source_requirements[name] || @source_requirements[:default]
end
def default_bundler_source
@source_requirements[:default_bundler]
end
def bundler_pinned_to_current_version?
!default_bundler_source.nil?
end
def name_for_explicit_dependency_source
Bundler.default_gemfile.basename.to_s
rescue StandardError
"Gemfile"
end
def raise_not_found!(package)
name = package.name
source = source_for(name)
specs = @all_specs[name]
matching_part = name
requirement_label = SharedHelpers.pretty_dependency(package.dependency)
cache_message = begin
" or in gems cached in #{Bundler.settings.app_cache_path}" if Bundler.app_cache.exist?
rescue GemfileNotFound
nil
end
specs_matching_requirement = filter_matching_specs(specs, package.dependency.requirement)
not_found_message = if specs_matching_requirement.any?
specs = specs_matching_requirement
matching_part = requirement_label
platforms = package.platforms
if platforms.size == 1
"Could not find gem '#{requirement_label}' with platform '#{platforms.first}'"
else
"Could not find gems matching '#{requirement_label}' valid for all resolution platforms (#{platforms.join(", ")})"
end
else
"Could not find gem '#{requirement_label}'"
end
message = String.new("#{not_found_message} in #{source}#{cache_message}.\n")
if specs.any?
message << "\n#{other_specs_matching_message(specs, matching_part)}"
end
raise GemNotFound, message
end
private
def filtered_versions_for(package)
@gem_version_promoter.filter_versions(package, @all_versions[package])
end
def raise_all_versions_filtered_out!(package)
level = @gem_version_promoter.level
name = package.name
locked_version = package.locked_version
requirement = package.dependency
raise GemNotFound,
"#{name} is locked to #{locked_version}, while Gemfile is requesting #{requirement}. " \
"--strict --#{level} was specified, but there are no #{level} level upgrades from #{locked_version} satisfying #{requirement}, so version solving has failed"
end
def filter_matching_specs(specs, requirements)
Array(requirements).flat_map do |requirement|
specs.select {| spec| requirement_satisfied_by?(requirement, spec) }
end
end
def filter_prereleases(specs, package)
return specs unless package.ignores_prereleases? && specs.size > 1
specs.reject {|s| s.version.prerelease? }
end
# Ignore versions that depend on themselves incorrectly
def filter_invalid_self_dependencies(specs, name)
specs.reject do |s|
s.dependencies.any? {|d| d.name == name && !d.requirement.satisfied_by?(s.version) }
end
end
def requirement_satisfied_by?(requirement, spec)
requirement.satisfied_by?(spec.version) || spec.source.is_a?(Source::Gemspec)
end
def sort_versions_by_preferred(package, versions)
@gem_version_promoter.sort_versions(package, versions)
end
def repository_for(package)
source_for(package.name)
end
def base_requirements
@base.base_requirements
end
def prepare_dependencies(requirements, packages)
to_dependency_hash(requirements, packages).map do |dep_package, dep_constraint|
name = dep_package.name
next [dep_package, dep_constraint] if name == "bundler"
dep_range = dep_constraint.range
versions = select_sorted_versions(dep_package, dep_range)
if versions.empty? && dep_package.ignores_prereleases?
@all_versions.delete(dep_package)
@sorted_versions.delete(dep_package)
dep_package.consider_prereleases!
versions = select_sorted_versions(dep_package, dep_range)
end
if versions.empty? && select_all_versions(dep_package, dep_range).any?
raise_all_versions_filtered_out!(dep_package)
end
next [dep_package, dep_constraint] unless versions.empty?
next unless dep_package.current_platform?
raise_not_found!(dep_package)
end.compact.to_h
end
def select_sorted_versions(package, range)
range.select_versions(@sorted_versions[package])
end
def select_all_versions(package, range)
range.select_versions(@all_versions[package])
end
def other_specs_matching_message(specs, requirement)
message = String.new("The source contains the following gems matching '#{requirement}':\n")
message << specs.map {|s| " * #{s.full_name}" }.join("\n")
message
end
def requirement_to_range(requirement)
ranges = requirement.requirements.map do |(op, version)|
ver = Resolver::Candidate.new(version).generic!
platform_ver = Resolver::Candidate.new(version).platform_specific!
case op
when "~>"
name = "~> #{ver}"
bump = Resolver::Candidate.new(version.bump.to_s + ".A")
PubGrub::VersionRange.new(name: name, min: ver, max: bump, include_min: true)
when ">"
PubGrub::VersionRange.new(min: platform_ver)
when ">="
PubGrub::VersionRange.new(min: ver, include_min: true)
when "<"
PubGrub::VersionRange.new(max: ver)
when "<="
PubGrub::VersionRange.new(max: platform_ver, include_max: true)
when "="
PubGrub::VersionRange.new(min: ver, max: platform_ver, include_min: true, include_max: true)
when "!="
PubGrub::VersionRange.new(min: ver, max: platform_ver, include_min: true, include_max: true).invert
else
raise "bad version specifier: #{op}"
end
end
ranges.inject(&:intersect)
end
def to_dependency_hash(dependencies, packages)
dependencies.inject({}) do |deps, dep|
package = packages[dep.name]
current_req = deps[package]
new_req = parse_dependency(package, dep.requirement)
deps[package] = if current_req
current_req.intersect(new_req)
else
new_req
end
deps
end
end
def bundler_not_found_message(conflict_dependencies)
candidate_specs = filter_matching_specs(default_bundler_source.specs.search("bundler"), conflict_dependencies)
if candidate_specs.any?
target_version = candidate_specs.last.version
new_command = [File.basename($PROGRAM_NAME), "_#{target_version}_", *ARGV].join(" ")
"Your bundle requires a different version of Bundler than the one you're running.\n" \
"Install the necessary version with `gem install bundler:#{target_version}` and rerun bundler using `#{new_command}`\n"
else
"Your bundle requires a different version of Bundler than the one you're running, and that version could not be found.\n"
end
end
end
end