pretty/test/test_analyze_structure.lua

local SUITE = require('TestSuite').new('analyze_structure')
SUITE:setEnviroment {
    analyze_structure = require('analyze_structure')[1],
    TABLE_TYPE        = require('table_type')
}

--------------------------------------------------------------------------------
-- analyze_structure

SUITE:addTest('Empty Table', function ()
    local input      = {} -- Empty!
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.EMPTY, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, false)
    assert_equal(table_info.has_map, false)
end)

SUITE:addTest('Sequence', function ()
    local input      = { 1, 2, 3 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.SEQUENCE, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, true)
    assert_equal(table_info.has_map, false)
end)

SUITE:addTest('Sequence with holes', function ()
    local input      = { 1, nil, 3 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.SEQUENCE, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, true)
    assert_equal(table_info.has_map, false)
    assert_equal(table_info.has_holes, true)
end)

SUITE:addTest('Sequence with hole on start', function ()
    local input      = { nil, 2, 3 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.SEQUENCE, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, true)
    assert_equal(table_info.has_map, false)
    assert_equal(table_info.has_holes, true)
end)

SUITE:addTest('Pure Map', function ()
    local input      = { a = 1, [true] = 2, c = 3 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.PURE_MAP, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, false)
    assert_equal(table_info.has_map, true)
end)

SUITE:addTest('Boolean set', function ()
    local input      = { [true] = true, [false] = false }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.SET, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, false)
    assert_equal(table_info.has_map, true)
end)

SUITE:addTest('A Mixed table', function ()
    local input      = { 300, [300] = 1 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.has_seq, true)
    assert_equal(table_info.has_map, true)
    assert_equal(table_info.type, TABLE_TYPE.MIXED, 'Returned bad type: '..table_info.type)
end)

SUITE:addTest('String Map', function ()
    local input      = { a = 1, b = 2, c = 3 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.STRING_MAP, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.has_seq, false)
    assert_equal(table_info.has_map, true)
end)

SUITE:addTest('Set', function ()
    local input      = { a = true, b = true, c = true }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.SET, 'Returned bad type: '..table_info.type)
    assert_equal(table_info.is_set, true)
end)

SUITE:addTest('Tabular of sequences', function ()
    local input      = { a = {1, 2, 3}, b = {4, 5, 6}, c = {7, 8, 9} }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.is_tabular, {true, true, true})
end)

SUITE:addTest('Tabular of maps', function ()
    local input      = { a = {a = 1, b = 2}, b = {a = 3, b = 4}, c = {a = 2, b = 7} }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.is_tabular, {a = true, b = true})
end)

SUITE:addTest('Not Tabular, due to no-sub-tables', function ()
    local input      = { a = 1, b = {4}, c = 7 }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.is_tabular, false)
end)

SUITE:addTest('Not Tabular, due to not being identical sub-tables', function ()
    local input      = { a = { a = 1 }, b = { b = 2 }, c = { c = 3 } }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.is_tabular, false)
end)

SUITE:addTest('Not Tabular, due to varying lengths', function ()
    local input      = { { 1 }, { 2, 3 }, { 4, 5, 6 } }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.is_tabular, false)
end)

--------------------------------------------------------------------------------
-- Stops at max_depth

SUITE:addTest('Has info for root, and children', function ()
    local input      = { { 1 }, { 2, 3 }, { 4, 5, 6 } }
    local table_info = analyze_structure(input, 1)

    assert(table_info[input])
    assert(table_info[input[1]])
    assert(table_info[input[2]])
    assert(table_info[input[3]])
end)

SUITE:addTest('Has info for root, but not children', function ()
    local input      = { { 1 }, { 2, 3 }, { 4, 5, 6 } }
    local table_info = analyze_structure(input, 0)

    assert(table_info[input])
    assert(not table_info[input[1]])
    assert(not table_info[input[2]])
    assert(not table_info[input[3]])
end)

--------------------------------------------------------------------------------
-- Corner cases.

SUITE:addTest('goto is special', function ()
    local input      = { ['goto'] = 'hi' }
    local table_info = analyze_structure(input)[input]

    assert_equal(table_info.type, TABLE_TYPE.PURE_MAP, 'Returned bad type: '..table_info.type)
end)

--------------------------------------------------------------------------------
-- analyze_structure

SUITE:addTest('Recursive Numeration, Simple', function ()
    local input = {}
          input[1] = input
    local info  = analyze_structure(input)

    assert(info[input].marker == 1)
end)

SUITE:addTest('Recursive Numeration, Multiple-appear', function ()
    local input = { {}, { {} } }
          input[1][1] = input[2][1]
    local info  = analyze_structure(input)

    assert(info[input[1][1]].marker == 1)
end)

SUITE:addTest('Recursive Numeration, Multiple at once', function ()
    local input = { {}, { {} } }
          input[1][1] = input[2][1]
          input[1][2] = input
    local info  = analyze_structure(input)

    assert(type(info[input[1][1]].marker) == 'number')
    assert(type(info[input].marker) == 'number')
end)

SUITE:addTest('Recursive Numeration, Through Keys', function ()
    local input = { }
          input[input] = input
    local info  = analyze_structure(input)

    assert(info[input].marker == 1)
end)

--------------------------------------------------------------------------------
-- Metatable shennanigens.

SUITE:addTest('Wont crash, even though metatable.__index throws errors', function ()
    local input = setmetatable({ 'hi', 'hello' }, {__index = function (_, k) error('Undefined access on key: '..k) end})
    local info  = analyze_structure(input)

    assert(true)
end)

SUITE:addTest('Can count elements, even though metatable.__index throws errors', function ()
    local input = setmetatable({ 'hi', 'hello' }, {__index = function (_, k) error('Undefined access on key: '..k) end})
    local info  = analyze_structure(input)

    assert_equal(info[input].seq_elems, 2)
end)

--------------------------------------------------------------------------------
-- Uniform structure

SUITE:addTest('Can detect uniform structure', function ()
    local input = { a = 'b', b = 'a' }
    local info  = analyze_structure(input)

    assert_equal(info[input].is_uniform, true)
end)

SUITE:addTest('Can detect uniform structure with different key value types', function ()
    local input = { a = 1, b = 4 }
    local info  = analyze_structure(input)

    assert_equal(info[input].is_uniform, true)
end)

SUITE:addTest('Can detect basic non-uniform structure', function ()
    local input = { a = 'b', b = 5 }
    local info  = analyze_structure(input)

    assert_equal(info[input].is_uniform, false)
end)

SUITE:addTest('Can detect pseudo-uniform structure with nested tables', function ()
    -- It's pseudo-uniform because of the child having uniform structure with
    -- equal number of elements.
    local input = { a = { d = 7 }, b = { p = 3 } }
    local info  = analyze_structure(input)

    assert_equal(info[input].is_uniform, true)
end)

SUITE:addTest('Can detect non-uniform structure with nested tables', function ()
    local input = { a = { 'a', 'b', 'c' }, b = { p = 3, 'hi' } }
    local info  = analyze_structure(input)

    assert_equal(info[input].is_uniform, false)
end)

-- TODO: Add predicate to check for pseudo-uniformness.

--------------------------------------------------------------------------------
-- API stuff

SUITE:addTest('next_mark does not escape', function ()
    local info  = analyze_structure( {} )
    assert(not info.next_mark)
end)

SUITE:addTest('We can extend an already existing info table', function ()
    local tab1, tab2  =  {}, {}
    local info  = analyze_structure( tab1 )
    analyze_structure( tab2, math.huge, info )
    assert(info[tab1])
    assert(info[tab2])
end)

SUITE:addTest('When we extend an info table, we retain the previous root', function ()
    local tab1, tab2  =  {}, {}
    local info  = analyze_structure( tab1 )
    analyze_structure( tab2, math.huge, info )
    assert(tab1 == info.root)
end)

--------------------------------------------------------------------------------

return SUITE