test_spec.rb

describe 'database' do
  before do
    `rm -rf test.db`
  end

  def run_script(commands)
    raw_output = nil
    IO.popen("./db test.db", "r+") do |pipe|
      commands.each do |command|
        begin
          pipe.puts command
        rescue Errno::EPIPE
          break
        end
      end

      pipe.close_write

      # Read entire output
      raw_output = pipe.gets(nil)
    end
    raw_output.split("\n")
  end

  it 'inserts and retrieves a row' do
    result = run_script([
      "insert 1 user1 person1@example.com",
      "select",
      ".exit",
    ])
    expect(result).to match_array([
      "db > Executed.",
      "db > (1, user1, person1@example.com)",
      "Executed.",
      "db > ",
    ])
  end

  it 'keeps data after closing connection' do
    result1 = run_script([
      "insert 1 user1 person1@example.com",
      ".exit",
    ])
    expect(result1).to match_array([
      "db > Executed.",
      "db > ",
    ])

    result2 = run_script([
      "select",
      ".exit",
    ])
    expect(result2).to match_array([
      "db > (1, user1, person1@example.com)",
      "Executed.",
      "db > ",
    ])
  end

  it 'prints error message when table is full' do
    script = (1..1401).map do |i|
      "insert #{i} user#{i} person#{i}@example.com"
    end
    script << ".exit"
    result = run_script(script)
    expect(result.last(2)).to match_array([
      "db > Executed.",
      "db > ",
    ])
  end

  it 'allows inserting strings that are the maximum length' do
    long_username = "a"*32
    long_email = "a"*255
    script = [
      "insert 1 #{long_username} #{long_email}",
      "select",
      ".exit",
    ]
    result = run_script(script)
    expect(result).to match_array([
      "db > Executed.",
      "db > (1, #{long_username}, #{long_email})",
      "Executed.",
      "db > ",
    ])
  end

  it 'prints error message if strings are too long' do
    long_username = "a"*33
    long_email = "a"*256
    script = [
      "insert 1 #{long_username} #{long_email}",
      "select",
      ".exit",
    ]
    result = run_script(script)
    expect(result).to match_array([
      "db > String is too long.",
      "db > Executed.",
      "db > ",
    ])
  end

  it 'prints an error message if id is negative' do
    script = [
      "insert -1 cstack foo@bar.com",
      "select",
      ".exit",
    ]
    result = run_script(script)
    expect(result).to match_array([
      "db > ID must be positive.",
      "db > Executed.",
      "db > ",
    ])
  end

  it 'prints an error message if there is a duplicate id' do
    script = [
      "insert 1 user1 person1@example.com",
      "insert 1 user1 person1@example.com",
      "select",
      ".exit",
    ]
    result = run_script(script)
    expect(result).to match_array([
      "db > Executed.",
      "db > Error: Duplicate key.",
      "db > (1, user1, person1@example.com)",
      "Executed.",
      "db > ",
    ])
  end

  it 'allows printing out the structure of a one-node btree' do
    script = [3, 1, 2].map do |i|
      "insert #{i} user#{i} person#{i}@example.com"
    end
    script << ".btree"
    script << ".exit"
    result = run_script(script)

    expect(result).to match_array([
      "db > Executed.",
      "db > Executed.",
      "db > Executed.",
      "db > Tree:",
      "- leaf (size 3)",
      "  - 1",
      "  - 2",
      "  - 3",
      "db > "
    ])
  end

  it 'allows printing out the structure of a 3-leaf-node btree' do
    script = (1..14).map do |i|
      "insert #{i} user#{i} person#{i}@example.com"
    end
    script << ".btree"
    script << "insert 15 user15 person15@example.com"
    script << ".exit"
    result = run_script(script)

    expect(result[14...(result.length)]).to match_array([
      "db > Tree:",
      "- internal (size 1)",
      "  - leaf (size 7)",
      "    - 1",
      "    - 2",
      "    - 3",
      "    - 4",
      "    - 5",
      "    - 6",
      "    - 7",
      "  - key 7",
      "  - leaf (size 7)",
      "    - 8",
      "    - 9",
      "    - 10",
      "    - 11",
      "    - 12",
      "    - 13",
      "    - 14",
      "db > Executed.",
      "db > ",
    ])
  end

  it 'allows printing out the structure of a 4-leaf-node btree' do
    script = [
      "insert 18 user18 person18@example.com",
      "insert 7 user7 person7@example.com",
      "insert 10 user10 person10@example.com",
      "insert 29 user29 person29@example.com",
      "insert 23 user23 person23@example.com",
      "insert 4 user4 person4@example.com",
      "insert 14 user14 person14@example.com",
      "insert 30 user30 person30@example.com",
      "insert 15 user15 person15@example.com",
      "insert 26 user26 person26@example.com",
      "insert 22 user22 person22@example.com",
      "insert 19 user19 person19@example.com",
      "insert 2 user2 person2@example.com",
      "insert 1 user1 person1@example.com",
      "insert 21 user21 person21@example.com",
      "insert 11 user11 person11@example.com",
      "insert 6 user6 person6@example.com",
      "insert 20 user20 person20@example.com",
      "insert 5 user5 person5@example.com",
      "insert 8 user8 person8@example.com",
      "insert 9 user9 person9@example.com",
      "insert 3 user3 person3@example.com",
      "insert 12 user12 person12@example.com",
      "insert 27 user27 person27@example.com",
      "insert 17 user17 person17@example.com",
      "insert 16 user16 person16@example.com",
      "insert 13 user13 person13@example.com",
      "insert 24 user24 person24@example.com",
      "insert 25 user25 person25@example.com",
      "insert 28 user28 person28@example.com",
      ".btree",
      ".exit",
    ]
    result = run_script(script)

    expect(result[30...(result.length)]).to match_array([
      "db > Tree:",
      "- internal (size 3)",
      "  - leaf (size 7)",
      "    - 1",
      "    - 2",
      "    - 3",
      "    - 4",
      "    - 5",
      "    - 6",
      "    - 7",
      "  - key 7",
      "  - leaf (size 8)",
      "    - 8",
      "    - 9",
      "    - 10",
      "    - 11",
      "    - 12",
      "    - 13",
      "    - 14",
      "    - 15",
      "  - key 15",
      "  - leaf (size 7)",
      "    - 16",
      "    - 17",
      "    - 18",
      "    - 19",
      "    - 20",
      "    - 21",
      "    - 22",
      "  - key 22",
      "  - leaf (size 8)",
      "    - 23",
      "    - 24",
      "    - 25",
      "    - 26",
      "    - 27",
      "    - 28",
      "    - 29",
      "    - 30",
      "db > ",
    ])
  end

  it 'allows printing out the structure of a 7-leaf-node btree' do
    script = [
      "insert 58 user58 person58@example.com",
      "insert 56 user56 person56@example.com",
      "insert 8 user8 person8@example.com",
      "insert 54 user54 person54@example.com",
      "insert 77 user77 person77@example.com",
      "insert 7 user7 person7@example.com",
      "insert 25 user25 person25@example.com",
      "insert 71 user71 person71@example.com",
      "insert 13 user13 person13@example.com",
      "insert 22 user22 person22@example.com",
      "insert 53 user53 person53@example.com",
      "insert 51 user51 person51@example.com",
      "insert 59 user59 person59@example.com",
      "insert 32 user32 person32@example.com",
      "insert 36 user36 person36@example.com",
      "insert 79 user79 person79@example.com",
      "insert 10 user10 person10@example.com",
      "insert 33 user33 person33@example.com",
      "insert 20 user20 person20@example.com",
      "insert 4 user4 person4@example.com",
      "insert 35 user35 person35@example.com",
      "insert 76 user76 person76@example.com",
      "insert 49 user49 person49@example.com",
      "insert 24 user24 person24@example.com",
      "insert 70 user70 person70@example.com",
      "insert 48 user48 person48@example.com",
      "insert 39 user39 person39@example.com",
      "insert 15 user15 person15@example.com",
      "insert 47 user47 person47@example.com",
      "insert 30 user30 person30@example.com",
      "insert 86 user86 person86@example.com",
      "insert 31 user31 person31@example.com",
      "insert 68 user68 person68@example.com",
      "insert 37 user37 person37@example.com",
      "insert 66 user66 person66@example.com",
      "insert 63 user63 person63@example.com",
      "insert 40 user40 person40@example.com",
      "insert 78 user78 person78@example.com",
      "insert 19 user19 person19@example.com",
      "insert 46 user46 person46@example.com",
      "insert 14 user14 person14@example.com",
      "insert 81 user81 person81@example.com",
      "insert 72 user72 person72@example.com",
      "insert 6 user6 person6@example.com",
      "insert 50 user50 person50@example.com",
      "insert 85 user85 person85@example.com",
      "insert 67 user67 person67@example.com",
      "insert 2 user2 person2@example.com",
      "insert 55 user55 person55@example.com",
      "insert 69 user69 person69@example.com",
      "insert 5 user5 person5@example.com",
      "insert 65 user65 person65@example.com",
      "insert 52 user52 person52@example.com",
      "insert 1 user1 person1@example.com",
      "insert 29 user29 person29@example.com",
      "insert 9 user9 person9@example.com",
      "insert 43 user43 person43@example.com",
      "insert 75 user75 person75@example.com",
      "insert 21 user21 person21@example.com",
      "insert 82 user82 person82@example.com",
      "insert 12 user12 person12@example.com",
      "insert 18 user18 person18@example.com",
      "insert 60 user60 person60@example.com",
      "insert 44 user44 person44@example.com",
      ".btree",
      ".exit",
    ]
    result = run_script(script)

    expect(result[64...(result.length)]).to match_array([
      "db > Tree:",
      "- internal (size 1)",
      "  - internal (size 2)",
      "    - leaf (size 7)",
      "      - 1",
      "      - 2",
      "      - 4",
      "      - 5",
      "      - 6",
      "      - 7",
      "      - 8",
      "    - key 8",
      "    - leaf (size 11)",
      "      - 9",
      "      - 10",
      "      - 12",
      "      - 13",
      "      - 14",
      "      - 15",
      "      - 18",
      "      - 19",
      "      - 20",
      "      - 21",
      "      - 22",
      "    - key 22",
      "    - leaf (size 8)",
      "      - 24",
      "      - 25",
      "      - 29",
      "      - 30",
      "      - 31",
      "      - 32",
      "      - 33",
      "      - 35",
      "  - key 35",
      "  - internal (size 3)",
      "    - leaf (size 12)",
      "      - 36",
      "      - 37",
      "      - 39",
      "      - 40",
      "      - 43",
      "      - 44",
      "      - 46",
      "      - 47",
      "      - 48",
      "      - 49",
      "      - 50",
      "      - 51",
      "    - key 51",
      "    - leaf (size 11)",
      "      - 52",
      "      - 53",
      "      - 54",
      "      - 55",
      "      - 56",
      "      - 58",
      "      - 59",
      "      - 60",
      "      - 63",
      "      - 65",
      "      - 66",
      "    - key 66",
      "    - leaf (size 7)",
      "      - 67",
      "      - 68",
      "      - 69",
      "      - 70",
      "      - 71",
      "      - 72",
      "      - 75",
      "    - key 75",
      "    - leaf (size 8)",
      "      - 76",
      "      - 77",
      "      - 78",
      "      - 79",
      "      - 81",
      "      - 82",
      "      - 85",
      "      - 86",
      "db > ",
    ])
  end

  it 'prints constants' do
    script = [
      ".constants",
      ".exit",
    ]
    result = run_script(script)

    expect(result).to match_array([
      "db > Constants:",
      "ROW_SIZE: 293",
      "COMMON_NODE_HEADER_SIZE: 6",
      "LEAF_NODE_HEADER_SIZE: 14",
      "LEAF_NODE_CELL_SIZE: 297",
      "LEAF_NODE_SPACE_FOR_CELLS: 4082",
      "LEAF_NODE_MAX_CELLS: 13",
      "db > ",
    ])
  end

  it 'prints all rows in a multi-level tree' do
    script = []
    (1..15).each do |i|
      script << "insert #{i} user#{i} person#{i}@example.com"
    end
    script << "select"
    script << ".exit"
    result = run_script(script)
    expect(result[15...result.length]).to match_array([
      "db > (1, user1, person1@example.com)",
      "(2, user2, person2@example.com)",
      "(3, user3, person3@example.com)",
      "(4, user4, person4@example.com)",
      "(5, user5, person5@example.com)",
      "(6, user6, person6@example.com)",
      "(7, user7, person7@example.com)",
      "(8, user8, person8@example.com)",
      "(9, user9, person9@example.com)",
      "(10, user10, person10@example.com)",
      "(11, user11, person11@example.com)",
      "(12, user12, person12@example.com)",
      "(13, user13, person13@example.com)",
      "(14, user14, person14@example.com)",
      "(15, user15, person15@example.com)",
      "Executed.", "db > ",
    ])
  end
end