tree-sitter/spec/integration/compile_grammar_spec.cc
Max Brunsfeld 727727623a Start work on unit test that edits python code
Signed-off-by: Nathan Sobo <nathan@github.com>
2016-12-20 13:10:18 -08:00

847 lines
26 KiB
C++

#include "spec_helper.h"
#include "runtime/alloc.h"
#include "helpers/load_language.h"
#include "helpers/stderr_logger.h"
#include "helpers/dedent.h"
#include "compiler/util/string_helpers.h"
#include <map>
static string fill_template(string input, map<string, string> parameters) {
string result = input;
for (const auto &pair : parameters) {
util::str_replace(&result, "{{" + pair.first + "}}", pair.second);
}
return result;
}
START_TEST
describe("compile_grammar", []() {
TSDocument *document;
before_each([&]() {
document = ts_document_new();
});
after_each([&]() {
ts_document_free(document);
});
auto assert_root_node = [&](const string &expected_string) {
TSNode root_node = ts_document_root_node(document);
char *node_string = ts_node_string(root_node, document);
AssertThat(node_string, Equals(expected_string));
ts_free(node_string);
};
describe("conflicts", [&]() {
it("can resolve shift/reduce conflicts using associativities", [&]() {
string grammar_template = R"JSON({
"name": "associativity_example",
"rules": {
"expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "math_operation"},
{"type": "SYMBOL", "name": "identifier"}
]
},
"math_operation": {
"type": "{{math_operation_prec_type}}",
"value": 0,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "+"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
"identifier": {
"type": "PATTERN",
"value": "[a-zA-Z]+"
}
}
})JSON";
// Ambiguity, which '+' applies first?
ts_document_set_input_string(document, "x+y+z");
TSCompileResult result = ts_compile_grammar(fill_template(grammar_template, {
{"math_operation_prec_type", "PREC"}
}).c_str());
AssertThat(result.error_message, Equals(dedent(R"MESSAGE(
Unresolved conflict for symbol sequence:
expression '+' expression '+'
Possible interpretations:
1: (math_operation expression '+' expression) '+'
2: expression '+' (math_operation expression '+' expression)
Possible resolutions:
1: Specify a left or right associativity in `math_operation`
2: Add a conflict for these rules: `math_operation`
)MESSAGE")));
result = ts_compile_grammar(fill_template(grammar_template, {
{"math_operation_prec_type", "PREC_LEFT"}
}).c_str());
ts_document_set_language(document, load_compile_result("associativity_example", result));
ts_document_parse(document);
assert_root_node("(expression (math_operation "
"(expression (math_operation (expression (identifier)) (expression (identifier)))) "
"(expression (identifier))))");
result = ts_compile_grammar(fill_template(grammar_template, {
{"math_operation_prec_type", "PREC_RIGHT"}
}).c_str());
ts_document_set_language(document, load_compile_result("associativity_example", result));
ts_document_parse(document);
assert_root_node("(expression (math_operation "
"(expression (identifier)) "
"(expression (math_operation (expression (identifier)) (expression (identifier))))))");
});
it("can resolve shift/reduce conflicts involving single-child rules using precedence", [&]() {
string grammar_template = R"JSON({
"name": "associativity_example",
"extras": [
{"type": "PATTERN", "value": "\\s"}
],
"rules": {
"expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "function_call"},
{"type": "SYMBOL", "name": "identifier"}
]
},
"function_call": {
"type": "PREC_RIGHT",
"value": {{function_call_precedence}},
"content": {
"type": "CHOICE",
"members": [
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "expression"}
]
},
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "block"}
]
},
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "expression"},
{"type": "SYMBOL", "name": "block"}
]
}
]
}
},
"block": {
"type": "SEQ",
"members": [
{"type": "STRING", "value": "{"},
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "}"}
]
},
"identifier": {
"type": "PATTERN",
"value": "[a-zA-Z]+"
}
}
})JSON";
// Ambiguity: is the trailing block associated with `bar` or `foo`?
ts_document_set_input_string(document, "foo bar { baz }");
TSCompileResult result = ts_compile_grammar(fill_template(grammar_template, {
{"function_call_precedence", "0"}
}).c_str());
AssertThat(result.error_message, Equals(dedent(R"MESSAGE(
Unresolved conflict for symbol sequence:
identifier '{'
Possible interpretations:
1: (expression identifier) '{'
2: (function_call identifier block)
Possible resolutions:
1: Specify a higher precedence in `function_call` than in the other rules.
2: Specify a higher precedence in `expression` than in the other rules.
3: Specify a left or right associativity in `expression`
4: Add a conflict for these rules: `expression` `function_call`
)MESSAGE")));
// Giving function calls lower precedence than expressions causes `bar`
// to be treated as an expression passed to `foo`, not as a function
// that's being called with a block.
result = ts_compile_grammar(fill_template(grammar_template, {
{"function_call_precedence", "-1"}
}).c_str());
AssertThat(result.error_message, IsNull());
ts_document_set_language(document, load_compile_result("associativity_example", result));
ts_document_parse(document);
assert_root_node("(expression (function_call "
"(identifier) "
"(expression (identifier)) "
"(block (expression (identifier)))))");
// Giving function calls higher precedence than expressions causes `bar`
// to be treated as a function that's being called with a block, not as
// an expression passed to `foo`.
result = ts_compile_grammar(fill_template(grammar_template, {
{"function_call_precedence", "1"}
}).c_str());
AssertThat(result.error_message, IsNull());
ts_document_set_language(document, load_compile_result("associativity_example", result));
ts_document_set_input_string(document, "foo bar { baz }");
ts_document_parse(document);
assert_root_node("(expression (function_call "
"(identifier) "
"(expression (function_call "
"(identifier) "
"(block (expression (identifier)))))))");
});
it("handles precedence applied to specific rule subsequences (regression)", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON({
"name": "precedence_on_subsequence",
"extras": [
{"type": "STRING", "value": " "}
],
"rules": {
"expression": {
"type": "PREC_LEFT",
"value": 0,
"content": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "function_call"},
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "scope_resolution"}
]
}
},
"function_call": {
"type": "CHOICE",
"members": [
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "expression"}
]
},
{
"type": "PREC",
"value": 1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "block"}
]
}
},
{
"type": "PREC",
"value": -1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{"type": "SYMBOL", "name": "do_block"}
]
}
},
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{
"type": "PREC",
"value": 1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "SYMBOL", "name": "block"}
]
}
}
]
},
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "identifier"},
{
"type": "PREC",
"value": -1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "SYMBOL", "name": "do_block"}
]
}
}
]
}
]
},
"scope_resolution": {
"type": "PREC_LEFT",
"value": 1,
"content": {
"type": "CHOICE",
"members": [
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "::"},
{"type": "SYMBOL", "name": "expression"}
]
},
{
"type": "SEQ",
"members": [
{"type": "STRING", "value": "::"},
{"type": "SYMBOL", "name": "expression"},
]
}
]
}
},
"block": {
"type": "STRING",
"value": "{}"
},
"do_block": {
"type": "STRING",
"value": "do end"
},
"identifier": {
"type": "PATTERN",
"value": "[a-zA-Z]+"
}
}
})JSON");
auto language = load_compile_result("precedence_on_subsequence", result);
ts_document_set_language(document, language);
ts_document_set_input_string(document, "a b {}");
ts_document_parse(document);
assert_root_node("(expression (function_call "
"(identifier) "
"(expression (function_call (identifier) (block)))))");
ts_document_set_input_string(document, "a b do end");
ts_document_parse(document);
assert_root_node("(expression (function_call "
"(identifier) "
"(expression (identifier)) "
"(do_block)))");
});
it("does not allow conflicting precedences", [&]() {
string grammar_template = R"JSON({
"name": "conflicting_precedence_example",
"rules": {
"expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "sum"},
{"type": "SYMBOL", "name": "product"},
{"type": "SYMBOL", "name": "other_thing"}
]
},
"sum": {
"type": "PREC_LEFT",
"value": 0,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "+"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
"product": {
"type": "PREC_LEFT",
"value": 1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "*"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
"other_thing": {
"type": "PREC_LEFT",
"value": -1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "*"},
{"type": "STRING", "value": "*"}
]
}
},
"identifier": {
"type": "PATTERN",
"value": "[a-zA-Z]+"
}
}
})JSON";
TSCompileResult result = ts_compile_grammar(fill_template(grammar_template, {
}).c_str());
AssertThat(result.error_message, Equals(dedent(R"MESSAGE(
Unresolved conflict for symbol sequence:
expression '+' expression '*'
Possible interpretations:
1: (sum expression '+' expression) '*'
2: expression '+' (product expression '*' expression)
3: expression '+' (other_thing expression '*' '*')
Possible resolutions:
1: Specify a higher precedence in `product` and `other_thing` than in the other rules.
2: Specify a higher precedence in `sum` than in the other rules.
3: Add a conflict for these rules: `sum` `product` `other_thing`
)MESSAGE")));
});
});
describe("when the grammar contains rules that match the empty string", [&]() {
it("reports an error", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON(
{
"name": "empty_rules",
"rules": {
"rule_1": {"type": "SYMBOL", "name": "rule_2"},
"rule_2": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "rule_1"},
{"type": "BLANK"}
]
}
}
}
)JSON");
AssertThat(result.error_message, Equals(dedent(R"MESSAGE(
The rule `rule_2` matches the empty string.
Tree-sitter currently does not support syntactic rules that match the empty string.
)MESSAGE")));
});
});
describe("external scanners", [&]() {
it("can tokenize using arbitrary user-defined scanner functions", [&]() {
string grammar = R"JSON({
"name": "external_scanner_example",
"externals": [
"_percent_string",
"_percent_string_start",
"_percent_string_end"
],
"extras": [
{"type": "PATTERN", "value": "\\s"}
],
"rules": {
"expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "string"},
{"type": "SYMBOL", "name": "sum"},
{"type": "SYMBOL", "name": "identifier"}
]
},
"sum": {
"type": "PREC_LEFT",
"value": 0,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "+"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
"string": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "_percent_string"},
{
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "_percent_string_start"},
{"type": "SYMBOL", "name": "expression"},
{"type": "SYMBOL", "name": "_percent_string_end"}
]
},
]
},
"identifier": {
"type": "PATTERN",
"value": "\\a+"
}
}
})JSON";
TSCompileResult result = ts_compile_grammar(grammar.c_str());
AssertThat(result.error_message, IsNull());
ts_document_set_language(document, load_compile_result(
"external_scanner_example",
result,
"spec/fixtures/external_scanners/percent_strings.c"
));
ts_document_set_input_string(document, "x + %(sup (external) scanner?)");
ts_document_parse(document);
assert_root_node("(expression (sum (expression (identifier)) (expression (string))))");
ts_document_set_input_string(document, "%{sup {} #{x + y} {} scanner?}");
ts_document_parse(document);
assert_root_node("(expression (string (expression (sum (expression (identifier)) (expression (identifier))))))");
});
it("allows external scanners to refer to tokens that are defined internally", [&]() {
string grammar = R"JSON({
"name": "shared_external_tokens",
"externals": [
"string",
"line_break"
],
"extras": [
{"type": "PATTERN", "value": "\\s"}
],
"rules": {
"statement": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "_expression"},
{"type": "SYMBOL", "name": "_expression"},
{"type": "SYMBOL", "name": "line_break"}
]
},
"_expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "string"},
{"type": "SYMBOL", "name": "variable"},
{"type": "SYMBOL", "name": "number"}
]
},
"variable": {"type": "PATTERN", "value": "\\a+"},
"number": {"type": "PATTERN", "value": "\\d+"},
"line_break": {"type": "STRING", "value": "\n"}
}
})JSON";
TSCompileResult result = ts_compile_grammar(grammar.c_str());
AssertThat(result.error_message, IsNull());
ts_document_set_language(document, load_compile_result(
"shared_external_tokens",
result,
"spec/fixtures/external_scanners/shared_external_tokens.c"
));
ts_document_set_input_string(document, "a b\n");
ts_document_parse(document);
assert_root_node("(statement (variable) (variable) (line_break))");
ts_document_set_input_string(document, "a \nb\n");
ts_document_parse(document);
assert_root_node("(statement (variable) (variable) (line_break))");
ts_document_set_input_string(document, "'hello' 'world'\n");
ts_document_parse(document);
assert_root_node("(statement (string) (string) (line_break))");
ts_document_set_input_string(document, "'hello' \n'world'\n");
ts_document_parse(document);
assert_root_node("(statement (string) (string) (line_break))");
});
it("allows external tokens to be used as extras", [&]() {
string grammar = R"JSON({
"name": "extra_external_tokens",
"externals": [
"comment"
],
"extras": [
{"type": "PATTERN", "value": "\\s"},
{"type": "SYMBOL", "name": "comment"}
],
"rules": {
"assignment": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "variable"},
{"type": "STRING", "value": "="},
{"type": "SYMBOL", "name": "variable"}
]
},
"variable": {"type": "PATTERN", "value": "\\a+"}
}
})JSON";
TSCompileResult result = ts_compile_grammar(grammar.c_str());
AssertThat(result.error_message, IsNull());
ts_document_set_language(document, load_compile_result(
"extra_external_tokens",
result,
"spec/fixtures/external_scanners/extra_external_tokens.c"
));
ts_document_set_input_string(document, "x = # a comment\n y");
ts_document_parse(document);
assert_root_node("(assignment (variable) (comment) (variable))");
});
});
describe("when the grammar's start symbol is a token", [&]() {
it("parses the token", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON(
{
"name": "one_token_language",
"rules": {
"first_rule": {"type": "STRING", "value": "the-value"}
}
}
)JSON");
ts_document_set_language(document, load_compile_result("one_token_language", result));
ts_document_set_input_string(document, "the-value");
ts_document_parse(document);
assert_root_node("(first_rule)");
});
});
describe("when the grammar's start symbol is blank", [&]() {
it("parses the empty string", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON(
{
"name": "blank_language",
"rules": {
"first_rule": {"type": "BLANK"}
}
}
)JSON");
ts_document_set_language(document, load_compile_result("blank_language", result));
ts_document_set_input_string(document, "");
ts_document_parse(document);
assert_root_node("(first_rule)");
});
});
describe("when the grammar contains anonymous tokens with escaped characters", [&]() {
it("escapes the escaped characters properly in the generated parser", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON(
{
"name": "escaped_char_language",
"rules": {
"first_rule": {
"type": "CHOICE",
"members": [
{"type": "STRING", "value": "\n"},
{"type": "STRING", "value": "\r"},
{"type": "STRING", "value": "'hello'"},
{"type": "PATTERN", "value": "\\d+"}
]
}
}
}
)JSON");
ts_document_set_language(document, load_compile_result("escaped_char_language", result));
ts_document_set_input_string(document, "1234");
ts_document_parse(document);
assert_root_node("(first_rule)");
ts_document_set_input_string(document, "\n");
ts_document_parse(document);
assert_root_node("(first_rule)");
ts_document_set_input_string(document, "'hello'");
ts_document_parse(document);
assert_root_node("(first_rule)");
});
});
describe("the grammar in the README", [&]() {
it("parses the input in the README", [&]() {
TSCompileResult result = ts_compile_grammar(R"JSON(
{
"name": "arithmetic",
// Things that can appear anywhere in the language, like comments
// and whitespace, are expressed as 'extras'.
"extras": [
{"type": "PATTERN", "value": "\\s"},
{"type": "SYMBOL", "name": "comment"}
],
"rules": {
// The first rule listed in the grammar becomes the 'start rule'.
"expression": {
"type": "CHOICE",
"members": [
{"type": "SYMBOL", "name": "sum"},
{"type": "SYMBOL", "name": "product"},
{"type": "SYMBOL", "name": "number"},
{"type": "SYMBOL", "name": "variable"},
{
"type": "SEQ",
"members": [
{"type": "STRING", "value": "("},
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": ")"}
]
}
]
},
// Tokens like '+' and '*' are described directly within the
// grammar's rules, as opposed to in a seperate lexer description.
"sum": {
"type": "PREC_LEFT",
"value": 1,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "+"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
// Ambiguities can be resolved at compile time by assigning precedence
// values to rule subtrees.
"product": {
"type": "PREC_LEFT",
"value": 2,
"content": {
"type": "SEQ",
"members": [
{"type": "SYMBOL", "name": "expression"},
{"type": "STRING", "value": "*"},
{"type": "SYMBOL", "name": "expression"}
]
}
},
// Tokens can be specified using ECMAScript regexps.
"number": {"type": "PATTERN", "value": "\\d+"},
"comment": {"type": "PATTERN", "value": "#.*"},
"variable": {"type": "PATTERN", "value": "[a-zA-Z]\\w*"}
}
}
)JSON");
const TSLanguage *language = load_compile_result("arithmetic", result);
ts_document_set_language(document, language);
ts_document_set_input_string(document, "a + b * c");
ts_document_parse(document);
assert_root_node(
"(expression (sum "
"(expression (variable)) "
"(expression (product "
"(expression (variable)) "
"(expression (variable))))))");
});
});
});
END_TEST