picopackage/test/test_package.rb

# frozen_string_literal: true

require "test_helper"

class TestPackage < Minitest::Test
  include PicopackageTest

  BARE = "def hello\n  :world\nend\n"

  def test_it_has_a_version_number
    refute_nil ::Picopackage::VERSION
  end

  def test_a_bare_file_is_bare
    assert Picopackage::Package.new(content: BARE).bare?
  end

  def test_a_generated_package_parses_back_as_a_package
    package = Picopackage::Package.new(content: BARE).init_metadata(filename: "hello.rb")
    round_tripped = Picopackage::Package.new(content: package.generate_package)

    refute_predicate round_tripped, :bare?
    assert_equal "hello.rb", round_tripped.filename
  end

  def test_reads_metadata_from_a_packaged_file
    package = Picopackage::Package.from_file("test/files/uniquify_array_packaged.rb")
    assert_equal "uniquify_array.rb", package.filename
    assert_equal "https://api.github.com/gists/525ac4177964549ee2f2ca7febd03eea", package.url
  end

  # This was the bug that made every file look locally modified: the checksum
  # written into a package hashed the un-normalised payload while verification
  # hashed the normalised one, so nothing ever verified against itself.
  def test_a_freshly_packaged_file_verifies_against_its_own_checksum
    package = Picopackage::Package.new(content: BARE).init_metadata(filename: "hello.rb")
    written = Picopackage::Package.new(content: package.generate_package)

    assert written.verify_payload, "a package should satisfy its own checksum"
    refute_predicate written, :modified?
  end

  def test_payload_digest_is_stable_across_packaging
    bare = Picopackage::Package.new(content: BARE)
    packaged = Picopackage::Package.new(
      content: Picopackage::Package.new(content: BARE).init_metadata(filename: "hello.rb").generate_package
    )

    assert_equal bare.payload_digest, packaged.payload_digest,
      "adding a metadata block must not change the payload digest"
  end

  def test_editing_a_payload_is_detected
    packaged = Picopackage::Package.new(content: BARE).init_metadata(filename: "hello.rb").generate_package
    edited = Picopackage::Package.new(content: packaged.sub(":world", ":everyone"))

    assert_predicate edited, :modified?
  end

  def test_unmodelled_metadata_keys_survive_a_rewrite
    content = <<~RUBY
      code_here

      # @PICOPACKAGE_START
      # ---
      # filename: thing.rb
      # licence: MIT
      # test_url: https://example.com/thing_test.rb
      # @PICOPACKAGE_END
    RUBY

    package = Picopackage::Package.new(content: content)
    assert_equal "MIT", package.metadata.extra["licence"]

    rewritten = Picopackage::Package.new(content: package.generate_package)
    assert_equal "MIT", rewritten.metadata.extra["licence"]
    assert_equal "https://example.com/thing_test.rb", rewritten.metadata.extra["test_url"]
  end

  # A checksum is derived, never preserved. An author who edits a packaged file
  # by hand and re-runs the tool must get a block describing what is now there,
  # not the value that happened to already be sitting in it.
  def test_a_stale_recorded_checksum_is_corrected_on_write
    content = "code\n\n# @PICOPACKAGE_START\n# ---\n# filename: thing.rb\n" \
              "# payload_checksum: sha256:#{"de" * 32}\n# @PICOPACKAGE_END\n"

    stale = Picopackage::Package.new(content: content)
    refute stale.verify_payload, "precondition: the recorded checksum is wrong"

    rewritten = Picopackage::Package.new(content: stale.generate_package)
    assert rewritten.verify_payload
    refute_predicate rewritten, :modified?
  end

  def test_a_block_of_only_unmodelled_keys_is_not_treated_as_bare
    content = "code\n\n# @PICOPACKAGE_START\n# ---\n# licence: MIT\n# @PICOPACKAGE_END\n"
    refute_predicate Picopackage::Package.new(content: content), :bare?,
      "a block we don't fully understand is still a block"
  end

  def test_malformed_front_matter_does_not_raise
    package = Picopackage::Package.from_file("test/files/broken_front_matter_1.rb")
    refute_nil package
    assert_predicate package.metadata, :empty?
  end
end