tree-sitter/spec/runtime/document_spec.cc

#include "runtime/runtime_spec_helper.h"
#include "runtime/helpers/spy_reader.h"
#include "runtime/tree.h"

extern "C" const TSLanguage * ts_language_json;

START_TEST

describe("incremental parsing", [&]() {
    TSDocument *doc;

    before_each([&]() {
        doc = ts_document_make();
        ts_document_set_language(doc, ts_language_json);
    });

    after_each([&]() {
        ts_document_free(doc);
    });

    describe("incremental parsing", [&]() {
        SpyReader *reader;

        before_each([&]() {
            reader = new SpyReader("{ \"key\": [1, 2] }", 5);
            ts_document_set_input(doc, reader->input);
        });

        after_each([&]() {
            delete reader;
        });

        it("parses the input", [&]() {
            AssertThat(string(ts_document_string(doc)), Equals(
                "(object (string) (array (number) (number)))"));
        });

        it("reads the entire input", [&]() {
            AssertThat(reader->strings_read, Equals(vector<string>({
                "{ \"key\": [1, 2] }"
            })));
        });

        describe("modifying the end of the input", [&]() {
            before_each([&]() {
                size_t position(string("{ \"key\": [1, 2]").length());
                string inserted_text(", \"key2\": 4");

                reader->content.insert(position, inserted_text);
                ts_document_edit(doc, { position, 0, inserted_text.length() });
            });

            it("updates the parse tree", [&]() {
                AssertThat(string(ts_document_string(doc)), Equals(
                    "(object (string) (array (number) (number)) (string) (number))"));
            });

            it("re-reads only the changed portion of the input", [&]() {
                AssertThat(reader->strings_read.size(), Equals<size_t>(2));
                AssertThat(reader->strings_read[1], Equals(", \"key2\": 4 }"));
            });
        });

        describe("modifying the beginning of the input", [&]() {
            before_each([&]() {
                size_t position(string("{ ").length());
                string inserted_text("\"key2\": 4, ");

                reader->content.insert(position, inserted_text);
                ts_document_edit(doc, { position, 0, inserted_text.length() });
            });

            it("updates the parse tree", [&]() {
                AssertThat(string(ts_document_string(doc)), Equals(
                    "(object (string) (number) (string) (array (number) (number)))"));
            });

            it_skip("re-reads only the changed portion of the input", [&]() {
                AssertThat(reader->strings_read.size(), Equals<size_t>(2));
                AssertThat(reader->strings_read[1], Equals("\"key2\": 4, "));
            });
        });
    });

});

END_TEST