#!/bin/bash
# Specification DSL test
#
#  Copyright (C) 2014, 2017 Mike Gerwitz
#
#  This file is part of shspec.
#
#  shspec is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# TODO: This is incompletely tested because the tests must be written as the
# system itself is written! Therefore, it is not presently capable of
# running all necessary assertions on itself.
#
# Note: this test case will run pretty slowly because it forks a new process
# for each expectation.
##


##
# It is necessary to test syntax in a separate process so we do not
# interfere with the existing stack
#
# This will take an arbitrary script from stdin and execute it
test-run()
{
  ( cd ../src && ./run-spec <( cat ) )
}


describe shspec:begin-spec
  it is a placeholder that exits successfully
    expect shspec:begin-spec
      to succeed
  end
end


describe describe
  it fails if not paired with an "'end'"
    expect test-run <<< '
      describe foo
      # no end
    '; to fail
  end

  it succeeds if paired with matching "'end'"
    expect test-run <<< '
      describe foo
      end
    '; to succeed
  end
end


describe it
  it fails within "'describe'" if not paired with an "'end'"
    expect test-run <<< '
      describe it test
        it will fail
        # no end
      end
    '; to fail
  end

  it succeeds within "'describe'" if paired with an "'end'"
    expect test-run <<< '
      describe it test
        it will succeed
        end
      end
    '; to succeed
  end
end


describe expect
  it fails when not within "'describe'"
    expect test-run <<< '
      describe will fail
        # not within it
        expect true; to succeed
      end
    '; to fail
  end

  it succeeds with "'to'" clause when when within "'describe'"
    expect test-run <<< '
      describe foo
        it will succeed
          expect true; to succeed
        end
      end
    '; to succeed
  end

  it fails when missing "'to'" clause of expectation
    expect test-run <<< '
      describe foo
        it will fail
          # no "to" clause
          expect true
        end
      end
    '; to fail
  end

  it cannot be "'end'd" before "'to'" clause
    expect test-run <<< '
      describe foo
        it will fail
          expect true
          # expectation is unfinished
          end
        end
      end
    '; to fail
  end


  # the "premise" is the command executed by the `expect' line
  describe premise
    it properly executes quoted command lines
      expect test-run <<< '
        chk() { test $# -eq 1; }
        describe foo
          it handles whitespace
            expect chk "foo bar"
              to succeed
          end
        end
      '; to succeed
    end

    # if result data are stored in a variable, the shell will remove
    # trailing whitespace, which is certainly _not_ what we want
    it retains trailing newlines
      expect test-run <<< '
        chk() { test $( wc -l ) -eq 3; }
        describe foo
          it retains trailing whitespace
            expect chk <<< "foomoo

                            "
              to succeed
          end
        end
      '; to succeed
    end

    # null bytes must be properly handled when comparing binary data
    it handles binary comparison with null bytes
      expect test-run <<< '
        input=007a0000
        chk() { test $( xxd -p ) == "$input"; }
        describe foo
          it handles null bytes
            expect chk < <( xxd -r -p <<< "$input" )
              to succeed
          end
        end
      '; to succeed
    end
  end


  # the expectation handler performs the assertion logic
  describe handler
    it is provided premise exit code as first argument
      expect test-run <<< '
        declare excode=123
        shspec:expect:chk() { test "$1" -eq $excode; }

        describe foo
          it exposes exit code
            expect exit $excode
              to chk
          end
        end
      '; to succeed
    end

    # the "remainder" clause is the portion of the sentence that follows the
    # execution of the expectation handler
    it is provided remainder clause after shift argument
      expect test-run <<< '
        declare remain="a b c"
        shspec:expect:chk()
        {
          shift "$2"
          test "$*" == "$remain"
        }

        describe foo
          it should expose remainder clause
            expect true
              to chk $remain
          end
        end
      '; to succeed
    end

    it receives premise output via stdin
      expect test-run <<< '
        declare str=foo
        shspec:expect:chk() { test "$(cat)" == "$str"; }

        describe foo
          it pipes command output
            expect echo "$str"
              to chk
          end
        end
      '; to succeed
    end

    # that is, if we use <<< to provide premise output from memory, a
    # newline will be added; we don't want that!
    it does not have newline added to premise output if missing
      expect test-run <<< '
        shspec:expect:chk() { test "$( wc -c )" -eq 0; }

        describe foo
          it should not add newline
            expect true
              to chk
          end
        end
      '; to succeed
    end
  end


  describe to
    it fails when missing assertion string
      expect test-run <<< '
        describe foo
          it will fail
            # missing assertion sting
            expect true; to
          end
        end
      '; to fail
    end

    it can only follow an "'expect'" clause
      expect test-run <<< '
        describe foo
          it will fail
            # does not follow expect clause
            to succeed
        end
      '; to fail
    end

    it will fail on unknwon expectation
      expect test-run <<< '
        describe foo
          it will fail
            expect true
              to ___some-invalid-expectation___
          end
        end
      '; to fail
    end

    it will fail when expectation fails
      expect test-run <<< '
        describe foo
          it will fail
            # true is not a failure
            expect true; to fail
          end
        end
      '; to fail
    end

    it will succeed when expectation succeeds
      expect test-run <<< '
        describe foo
          it will succeed
            expect false; to fail
          end
        end
      '; to succeed
    end
  end


  describe and
    # technically, we want this to be permitted after any declaration, but
    # we do not yet support any others
    it must appear after a "'to'" declaration
      expect test-run <<< '
        describe foo
          it should fail
            expect true
              # missing "to"
              and to succeed
          end
        end
      '; to fail
    end

    it adds additional expectations to preceding declaration
      # impossible condition
      expect test-run <<< '
        describe foo
          it should fail
            expect true
              to succeed
              and to fail
          end
        end
      '; to fail

      # redundant to demonstrate that it does not always fail
      expect test-run <<< '
        describe foo
          it should fail
            expect true
              to succeed
              and to succeed
          end
        end
      '; to succeed
    end
  end


  describe shspec:proxy-to
    it proxies remainder clause with variable shift length
      expect test-run <<< '
        expected="foo bar baz"
        shspec:expect:chk() { shift "$2"; test "$*" == "$expected"; }

        describe foo
          it should succeed
            expect shspec:proxy-to 0 2 chk $expected
              to succeed

            expect shspec:proxy-to 0 3 /dev/null chk $expected
              to succeed
          end
        end
      '; to succeed
    end
  end
end