4 files changed, 357 insertions, 0 deletions
diff --git a/test/unit/eval/decode_spec.lua b/test/unit/eval/decode_spec.lua
new file mode 100644
index 0000000000..d94d809c14
--- /dev/null
+++ b/test/unit/eval/decode_spec.lua
@@ -0,0 +1,142 @@
+local helpers = require('test.unit.helpers')
+
+local cimport = helpers.cimport
+local to_cstr = helpers.to_cstr
+local eq = helpers.eq
+local neq = helpers.neq
+local ffi = helpers.ffi
+
+local decode = cimport('./src/nvim/eval/decode.h', './src/nvim/eval_defs.h',
+                       './src/nvim/globals.h', './src/nvim/memory.h',
+                       './src/nvim/message.h')
+
+describe('json_decode_string()', function()
+  local saved_p_enc = nil
+
+  before_each(function()
+    saved_p_enc = decode.p_enc
+  end)
+
+  after_each(function()
+    decode.emsg_silent = 0
+    decode.p_enc = saved_p_enc
+    while decode.delete_first_msg() == 1 do
+      -- Delete all messages
+    end
+  end)
+
+  local char = function(c)
+    return ffi.gc(decode.xmemdup(c, 1), decode.xfree)
+  end
+
+  it('does not overflow when running with `n…`, `t…`, `f…`', function()
+    local rettv = ffi.new('typval_T', {v_type=decode.VAR_UNKNOWN})
+    decode.emsg_silent = 1
+    -- This will not crash, but if `len` argument will be ignored it will parse 
+    -- `null` as `null` and if not it will parse `null` as `n`.
+    eq(0, decode.json_decode_string('null', 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('true', 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('false', 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('null', 2, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('true', 2, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('false', 2, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('null', 3, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('true', 3, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('false', 3, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('false', 4, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+  end)
+
+  it('does not overflow and crash when running with `n`, `t`, `f`', function()
+    local rettv = ffi.new('typval_T', {v_type=decode.VAR_UNKNOWN})
+    decode.emsg_silent = 1
+    eq(0, decode.json_decode_string(char('n'), 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string(char('t'), 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string(char('f'), 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+  end)
+
+  it('does not overflow when running with `"…`', function()
+    local rettv = ffi.new('typval_T', {v_type=decode.VAR_UNKNOWN})
+    decode.emsg_silent = 1
+    eq(0, decode.json_decode_string('"t"', 2, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    eq(0, decode.json_decode_string('""', 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+  end)
+
+  local check_failure = function(s, len, msg)
+    local rettv = ffi.new('typval_T', {v_type=decode.VAR_UNKNOWN})
+    eq(0, decode.json_decode_string(s, len, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+    neq(nil, decode.last_msg_hist)
+    eq(msg, ffi.string(decode.last_msg_hist.msg))
+  end
+
+  it('does not overflow in error messages', function()
+    check_failure(']test', 1, 'E474: No container to close: ]')
+    check_failure('[}test', 2, 'E474: Closing list with curly bracket: }')
+    check_failure('{]test', 2,
+                  'E474: Closing dictionary with square bracket: ]')
+    check_failure('[1,]test', 4, 'E474: Trailing comma: ]')
+    check_failure('{"1":}test', 6, 'E474: Expected value after colon: }')
+    check_failure('{"1"}test', 5, 'E474: Expected value: }')
+    check_failure(',test', 1, 'E474: Comma not inside container: ,')
+    check_failure('[1,,1]test', 6, 'E474: Duplicate comma: ,1]')
+    check_failure('{"1":,}test', 7, 'E474: Comma after colon: ,}')
+    check_failure('{"1",}test', 6, 'E474: Using comma in place of colon: ,}')
+    check_failure('{,}test', 3, 'E474: Leading comma: ,}')
+    check_failure('[,]test', 3, 'E474: Leading comma: ,]')
+    check_failure(':test', 1, 'E474: Colon not inside container: :')
+    check_failure('[:]test', 3, 'E474: Using colon not in dictionary: :]')
+    check_failure('{:}test', 3, 'E474: Unexpected colon: :}')
+    check_failure('{"1"::1}test', 8, 'E474: Duplicate colon: :1}')
+    check_failure('ntest', 1, 'E474: Expected null: n')
+    check_failure('ttest', 1, 'E474: Expected true: t')
+    check_failure('ftest', 1, 'E474: Expected false: f')
+    check_failure('"\\test', 2, 'E474: Unfinished escape sequence: "\\')
+    check_failure('"\\u"test', 4,
+                  'E474: Unfinished unicode escape sequence: "\\u"')
+    check_failure('"\\uXXXX"est', 8,
+                  'E474: Expected four hex digits after \\u: \\uXXXX"')
+    check_failure('"\\?"test', 4, 'E474: Unknown escape sequence: \\?"')
+    check_failure(
+        '"\t"test', 3,
+        'E474: ASCII control characters cannot be present inside string: \t"')
+    check_failure('"\194"test', 3, 'E474: Only UTF-8 strings allowed: \194"')
+    check_failure('"\252\144\128\128\128\128"test', 8, 'E474: Only UTF-8 code points up to U+10FFFF are allowed to appear unescaped: \252\144\128\128\128\128"')
+    check_failure('"test', 1, 'E474: Expected string end: "')
+    decode.p_enc = to_cstr('latin1')
+    check_failure('"\\uABCD"test', 8,
+                  'E474: Failed to convert string "ꯍ" from UTF-8')
+    decode.p_enc = saved_p_enc
+    check_failure('-test', 1, 'E474: Missing number after minus sign: -')
+    check_failure('-1.test', 3, 'E474: Missing number after decimal dot: -1.')
+    check_failure('-1.0etest', 5, 'E474: Missing exponent: -1.0e')
+    check_failure('?test', 1, 'E474: Unidentified byte: ?')
+    check_failure('1?test', 2, 'E474: Trailing characters: ?')
+    check_failure('[1test', 2, 'E474: Unexpected end of input: [1')
+  end)
+
+  it('does not overflow with `-`', function()
+    check_failure('-0', 1, 'E474: Missing number after minus sign: -')
+  end)
+
+  it('does not overflow and crash when running with `"`', function()
+    local rettv = ffi.new('typval_T', {v_type=decode.VAR_UNKNOWN})
+    decode.emsg_silent = 1
+    eq(0, decode.json_decode_string(char('"'), 1, rettv))
+    eq(decode.VAR_UNKNOWN, rettv.v_type)
+  end)
+end)
diff --git a/test/unit/eval/encode_spec.lua b/test/unit/eval/encode_spec.lua
new file mode 100644
index 0000000000..f151a191fb
--- /dev/null
+++ b/test/unit/eval/encode_spec.lua
@@ -0,0 +1,100 @@
+local helpers = require('test.unit.helpers')
+local eval_helpers = require('test.unit.eval.helpers')
+
+local cimport = helpers.cimport
+local to_cstr = helpers.to_cstr
+local eq = helpers.eq
+
+local list = eval_helpers.list
+local lst2tbl = eval_helpers.lst2tbl
+local type_key = eval_helpers.type_key
+local list_type = eval_helpers.list_type
+local null_string = eval_helpers.null_string
+
+local encode = cimport('./src/nvim/eval/encode.h')
+
+describe('encode_list_write()', function()
+  local encode_list_write = function(l, s)
+    return encode.encode_list_write(l, to_cstr(s), #s)
+  end
+
+  it('writes empty string', function()
+    local l = list()
+    eq(0, encode_list_write(l, ''))
+    eq({[type_key]=list_type}, lst2tbl(l))
+  end)
+
+  it('writes ASCII string literal with printable characters', function()
+    local l = list()
+    eq(0, encode_list_write(l, 'abc'))
+    eq({[type_key]=list_type, 'abc'}, lst2tbl(l))
+  end)
+
+  it('writes string starting with NL', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\nabc'))
+    eq({[type_key]=list_type, null_string, 'abc'}, lst2tbl(l))
+  end)
+
+  it('writes string starting with NL twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\nabc'))
+    eq({[type_key]=list_type, null_string, 'abc'}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\nabc'))
+    eq({[type_key]=list_type, null_string, 'abc', 'abc'}, lst2tbl(l))
+  end)
+
+  it('writes string ending with NL', function()
+    local l = list()
+    eq(0, encode_list_write(l, 'abc\n'))
+    eq({[type_key]=list_type, 'abc', null_string}, lst2tbl(l))
+  end)
+
+  it('writes string ending with NL twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, 'abc\n'))
+    eq({[type_key]=list_type, 'abc', null_string}, lst2tbl(l))
+    eq(0, encode_list_write(l, 'abc\n'))
+    eq({[type_key]=list_type, 'abc', 'abc', null_string}, lst2tbl(l))
+  end)
+
+  it('writes string starting, ending and containing NL twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\na\nb\n'))
+    eq({[type_key]=list_type, null_string, 'a', 'b', null_string}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\na\nb\n'))
+    eq({[type_key]=list_type, null_string, 'a', 'b', null_string, 'a', 'b', null_string}, lst2tbl(l))
+  end)
+
+  it('writes string starting, ending and containing NUL with NL between twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\0\n\0\n\0'))
+    eq({[type_key]=list_type, '\n', '\n', '\n'}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\0\n\0\n\0'))
+    eq({[type_key]=list_type, '\n', '\n', '\n\n', '\n', '\n'}, lst2tbl(l))
+  end)
+
+  it('writes string starting, ending and containing NL with NUL between twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\n\0\n\0\n'))
+    eq({[type_key]=list_type, null_string, '\n', '\n', null_string}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\n\0\n\0\n'))
+    eq({[type_key]=list_type, null_string, '\n', '\n', null_string, '\n', '\n', null_string}, lst2tbl(l))
+  end)
+
+  it('writes string containing a single NL twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\n'))
+    eq({[type_key]=list_type, null_string, null_string}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\n'))
+    eq({[type_key]=list_type, null_string, null_string, null_string}, lst2tbl(l))
+  end)
+
+  it('writes string containing a few NLs twice', function()
+    local l = list()
+    eq(0, encode_list_write(l, '\n\n\n'))
+    eq({[type_key]=list_type, null_string, null_string, null_string, null_string}, lst2tbl(l))
+    eq(0, encode_list_write(l, '\n\n\n'))
+    eq({[type_key]=list_type, null_string, null_string, null_string, null_string, null_string, null_string, null_string}, lst2tbl(l))
+  end)
+end)
diff --git a/test/unit/eval/helpers.lua b/test/unit/eval/helpers.lua
new file mode 100644
index 0000000000..2367f03e0d
--- /dev/null
+++ b/test/unit/eval/helpers.lua
@@ -0,0 +1,72 @@
+local helpers = require('test.unit.helpers')
+
+local cimport = helpers.cimport
+local to_cstr = helpers.to_cstr
+local ffi = helpers.ffi
+local eq = helpers.eq
+
+local eval = cimport('./src/nvim/eval.h', './src/nvim/eval_defs.h')
+
+local null_string = {[true]='NULL string'}
+local null_list = {[true]='NULL list'}
+local type_key = {[true]='type key'}
+local list_type = {[true]='list type'}
+
+local function list(...)
+  local ret = ffi.gc(eval.list_alloc(), eval.list_unref)
+  eq(0, ret.lv_refcount)
+  ret.lv_refcount = 1
+  for i = 1, select('#', ...) do
+    local val = select(i, ...)
+    local typ = type(val)
+    if typ == 'string' then
+      eval.list_append_string(ret, to_cstr(val))
+    elseif typ == 'table' and val == null_string then
+      eval.list_append_string(ret, nil)
+    elseif typ == 'table' and val == null_list then
+      eval.list_append_list(ret, nil)
+    elseif typ == 'table' and val[type_key] == list_type then
+      local itemlist = ffi.gc(list(table.unpack(val)), nil)
+      eq(1, itemlist.lv_refcount)
+      itemlist.lv_refcount = 0
+      eval.list_append_list(ret, itemlist)
+    else
+      assert(false, 'Not implemented yet')
+    end
+  end
+  return ret
+end
+
+local lst2tbl = function(l)
+  local ret = {[type_key]=list_type}
+  if l == nil then
+    return ret
+  end
+  local li = l.lv_first
+  -- (listitem_T *) NULL is equal to nil, but yet it is not false.
+  while li ~= nil do
+    local typ = li.li_tv.v_type
+    if typ == eval.VAR_STRING then
+      local str = li.li_tv.vval.v_string
+      if str == nil then
+        ret[#ret + 1] = null_string
+      else
+        ret[#ret + 1] = ffi.string(str)
+      end
+    else
+      assert(false, 'Not implemented yet')
+    end
+    li = li.li_next
+  end
+  return ret
+end
+
+return {
+  null_string=null_string,
+  null_list=null_list,
+  list_type=list_type,
+  type_key=type_key,
+
+  list=list,
+  lst2tbl=lst2tbl,
+}
diff --git a/test/unit/eval/tricks_spec.lua b/test/unit/eval/tricks_spec.lua
new file mode 100644
index 0000000000..4c5184995c
--- /dev/null
+++ b/test/unit/eval/tricks_spec.lua
@@ -0,0 +1,43 @@
+local helpers = require('test.unit.helpers')
+
+local cimport = helpers.cimport
+local to_cstr = helpers.to_cstr
+local ffi = helpers.ffi
+local eq = helpers.eq
+
+local eval = cimport('./src/nvim/eval.h', './src/nvim/memory.h')
+
+local eval_expr = function(expr)
+  return ffi.gc(eval.eval_expr(to_cstr(expr), nil), function(tv)
+    eval.clear_tv(tv)
+    eval.xfree(tv)
+  end)
+end
+
+describe('NULL typval_T', function()
+  it('is produced by $XXX_UNEXISTENT_VAR_XXX', function()
+    -- Required for various tests which need to check whether typval_T with NULL
+    -- string works correctly. This test checks that unexistent environment
+    -- variable produces NULL string, not that some specific environment
+    -- variable does not exist. Last bit is left for the test writers.
+    local unexistent_env = 'XXX_UNEXISTENT_VAR_XXX'
+    while os.getenv(unexistent_env) ~= nil do
+      unexistent_env = unexistent_env .. '_XXX'
+    end
+    local rettv = eval_expr('$' .. unexistent_env)
+    eq(eval.VAR_STRING, rettv.v_type)
+    eq(nil, rettv.vval.v_string)
+  end)
+
+  it('is produced by v:_null_list', function()
+    local rettv = eval_expr('v:_null_list')
+    eq(eval.VAR_LIST, rettv.v_type)
+    eq(nil, rettv.vval.v_list)
+  end)
+
+  it('is produced by v:_null_dict', function()
+    local rettv = eval_expr('v:_null_dict')
+    eq(eval.VAR_DICT, rettv.v_type)
+    eq(nil, rettv.vval.v_dict)
+  end)
+end)