Module: RSpec::StubbedEnv::StubHelpers

Included in:
HideHelpers
Defined in:
lib/rspec/stubbed_env/stub_helpers.rb

Overview

Helpers to unobtrusively stub ENV

Instance Method Summary collapse

Instance Method Details

#env_stubbed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 58

def env_stubbed?
  instance_variable_defined?(:@__rspec_stubbed_env_mutations) && !@__rspec_stubbed_env_mutations.empty?
end

#init_stub ⇒ Object 



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 62

def init_stub
  @__rspec_stubbed_env_mutations ||= []
  install_env_accessors
  add_stubbed_value(STUBBED_KEY, true, :track => false)
end

#install_env_accessors ⇒ Object

Install ONE block-backed receive per accessor instead of per-key
.with(key) expectations. Per-key expectations collide when the same
key is stubbed again in a later example after the earlier expectation
has been invoked — rspec-mocks raises “message expectation … has
already been invoked and cannot be modified further” (observed as a
seed-dependent CI failure). The blocks read the mutation ledger at
call time, so later stub_env / hide_env calls only append to it.



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 75

def install_env_accessors
  allow(ENV).to(receive(:[]) { |key| mixed_env_hash[key] })
  allow(ENV).to(receive(:fetch) do |key, *rest, &default_block|
    hidden = @__rspec_stubbed_env_mutations.reverse.any? do |op, k, _|
      op == :hide && k == key
    end
    value = mixed_env_hash[key]
    if hidden && value.nil?
      unless rest.empty?
        next rest.first
      end
      next default_block.call if default_block

      raise KeyError, %(key not found: "#{key}")
    end
    if value.nil?
      next rest.first unless rest.empty?
      next default_block.call if default_block
    end

    value
  end)
  allow(ENV).to(receive(:values_at)) do |*args|
    args.map { |arg| mixed_env_hash[arg] }
  end
end

#mixed_env_hash ⇒ Object 



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 112

def mixed_env_hash
  @__rspec_stubbed_env_mutations.each_with_object(ENV.each_pair.to_h) do |mutation, hash|
    operation, key, value = mutation
    case operation
    when :stub
      value.nil? ? hash.delete(key) : hash[key] = value
    when :hide
      hash.delete(key)
    end
  end
end

#remember_hidden_key(key) ⇒ Object 



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 107

def remember_hidden_key(key)
  @__rspec_stubbed_env_mutations ||= []
  @__rspec_stubbed_env_mutations << [:hide, key]
end

#remember_stubbed_value(key, value) ⇒ Object 



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 102

def remember_stubbed_value(key, value)
  @__rspec_stubbed_env_mutations ||= []
  @__rspec_stubbed_env_mutations << [:stub, key, value]
end

#stub_env(key_or_hash, value = nil) ⇒ Object

Can be called with all key value pairs to be stubbed as a hash:

stub_env('A' => 'B', 'C' => 'D', 'E' => 'F') # Preferred

Alternatively can be called one per ENV key-value pair to stub:

stub_env('A', 'B') # NOT
stub_env('C', 'D') # AS
stub_env('E', 'F') # GOOD (Creates redundant stubs on values_at)



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 40

def stub_env(key_or_hash, value = nil)
  init_stub unless env_stubbed?
  if key_or_hash.is_a?(Hash)
    key_or_hash.each { |k, v| add_stubbed_value(k, v) }
  else
    add_stubbed_value(key_or_hash, value)
  end
end

#stub_env_hash_accessors ⇒ Object

Opt in to stubbing ENV hash accessors. By default, stub_env only stubs
ENV[], ENV.fetch, and ENV.values_at so partial ENV stubs stay narrowly
scoped.



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# File 'lib/rspec/stubbed_env/stub_helpers.rb', line 52

def stub_env_hash_accessors
  init_stub unless env_stubbed?
  allow(ENV).to(receive(:to_hash) { mixed_env_hash })
  allow(ENV).to(receive(:to_h) { mixed_env_hash })
end