Tests of the JSONSelect lexer

Simple tokens
$ JSONSelect._lex(">");
[1, ">"]
$ JSONSelect._lex("*");
[1, "*"]
$ JSONSelect._lex(",");
[1, ","]
$ JSONSelect._lex(".");
[1, "."]
Offsets
$ JSONSelect._lex("foobar>",6);
[7, ">"]
Types
$ JSONSelect._lex("string");
[6, 3, "string"]
$ JSONSelect._lex("boolean");
[7, 3, "boolean"]
$ JSONSelect._lex("null");
[4, 3, "null"]
$ JSONSelect._lex("array");
[5, 3, "array"]
$ JSONSelect._lex("object");
[6, 3, "object"]
$ JSONSelect._lex("number");
[6, 3, "number"]
Whitespace
$ JSONSelect._lex("\r");
[1, " "]
$ JSONSelect._lex("\n");
[1, " "]
$ JSONSelect._lex("\t");
[1, " "]
$ JSONSelect._lex(" ");
[1, " "]
$ JSONSelect._lex("     \t   \r\n  !");
[13, " "]
pseudo classes
$ JSONSelect._lex(":root");
[5, 1, ":root"]
$ JSONSelect._lex(":first-child");
[12, 1, ":first-child"]
$ JSONSelect._lex(":last-child");
[11, 1, ":last-child"]
$ JSONSelect._lex(":only-child");
[11, 1, ":only-child"]
json strings
$ JSONSelect._lex('"foo bar baz"');
[13, 4, "foo bar baz"]
$ JSONSelect._lex('"\\u0020"');
[8, 4, " "]
$ JSONSelect._lex('\"not terminated');
Error: unclosed json string
$ JSONSelect._lex('"invalid escape: \\y"');
Error: invalid json string
identifiers (like after '.')
$ JSONSelect._lex("foo");
[3, 4, "foo"]
$ JSONSelect._lex("foo\\ bar");
[8, 4, "foo bar"]
$ JSONSelect._lex("_aB129bcde-\\:foo\\@$");
[18, 4, "_aB129bcde-:foo@"]
non-ascii
$ JSONSelect._lex("обичам\\ те\\!");
[12, 4, "обичам те!"]