tree-sitter/lib/binding_web/test/parser-test.js

const {assert} = require('chai');
let Parser; let JavaScript; let HTML; let languageURL;

describe('Parser', () => {
  let parser;

  before(async () =>
    ({Parser, JavaScript, HTML, languageURL} = await require('./helper')),
  );

  beforeEach(() => {
    parser = new Parser();
  });

  afterEach(() => {
    parser.delete();
  });

  describe('.setLanguage', () => {
    it('allows setting the language to null', () => {
      assert.equal(parser.getLanguage(), null);
      parser.setLanguage(JavaScript);
      assert.equal(parser.getLanguage(), JavaScript);
      parser.setLanguage(null);
      assert.equal(parser.getLanguage(), null);
    });

    it('throws an exception when the given object is not a tree-sitter language', () => {
      assert.throws(() => parser.setLanguage({}), /Argument must be a Language/);
      assert.throws(() => parser.setLanguage(1), /Argument must be a Language/);
    });
  });

  describe('.setLogger', () => {
    beforeEach(() => {
      parser.setLanguage(JavaScript);
    });

    it('calls the given callback for each parse event', () => {
      const debugMessages = [];
      parser.setLogger((message) => debugMessages.push(message));
      parser.parse('a + b + c');
      assert.includeMembers(debugMessages, [
        'skip character:\' \'',
        'consume character:\'b\'',
        'reduce sym:program, child_count:1',
        'accept',
      ]);
    });

    it('allows the callback to be retrieved later', () => {
      const callback = () => {};
      parser.setLogger(callback);
      assert.equal(parser.getLogger(), callback);
      parser.setLogger(false);
      assert.equal(parser.getLogger(), null);
    });

    it('disables debugging when given a falsy value', () => {
      const debugMessages = [];
      parser.setLogger((message) => debugMessages.push(message));
      parser.setLogger(false);
      parser.parse('a + b * c');
      assert.equal(debugMessages.length, 0);
    });

    it('throws an error when given a truthy value that isn\'t a function ', () => {
      assert.throws(
        () => parser.setLogger('5'),
        'Logger callback must be a function',
      );
    });

    it('rethrows errors thrown by the logging callback', () => {
      const error = new Error('The error message');
      parser.setLogger((_msg, _params) => {
        throw error;
      });
      assert.throws(
        () => parser.parse('ok;'),
        'The error message',
      );
    });
  });

  describe('one included range', () => {
    it('parses the text within a range', () => {
      parser.setLanguage(HTML);
      const sourceCode = '<span>hi</span><script>console.log(\'sup\');</script>';
      const htmlTree = parser.parse(sourceCode);
      const scriptContentNode = htmlTree.rootNode.child(1).child(1);
      assert.equal(scriptContentNode.type, 'raw_text');

      parser.setLanguage(JavaScript);
      assert.deepEqual(parser.getIncludedRanges(), [{
        startIndex: 0,
        endIndex: 2147483647,
        startPosition: {row: 0, column: 0},
        endPosition: {row: 4294967295, column: 2147483647},
      }]);
      const ranges = [{
        startIndex: scriptContentNode.startIndex,
        endIndex: scriptContentNode.endIndex,
        startPosition: scriptContentNode.startPosition,
        endPosition: scriptContentNode.endPosition,
      }];
      const jsTree = parser.parse(
        sourceCode,
        null,
        {includedRanges: ranges},
      );
      assert.deepEqual(parser.getIncludedRanges(), ranges);

      assert.equal(
        jsTree.rootNode.toString(),
        '(program (expression_statement (call_expression ' +
        'function: (member_expression object: (identifier) property: (property_identifier)) ' +
        'arguments: (arguments (string (string_fragment))))))',
      );
      assert.deepEqual(jsTree.rootNode.startPosition, {row: 0, column: sourceCode.indexOf('console')});
    });
  });

  describe('multiple included ranges', () => {
    it('parses the text within multiple ranges', () => {
      parser.setLanguage(JavaScript);
      const sourceCode = 'html `<div>Hello, ${name.toUpperCase()}, it\'s <b>${now()}</b>.</div>`';
      const jsTree = parser.parse(sourceCode);
      const templateStringNode = jsTree.rootNode.descendantForIndex(sourceCode.indexOf('`<'), sourceCode.indexOf('>`'));
      assert.equal(templateStringNode.type, 'template_string');

      const openQuoteNode = templateStringNode.child(0);
      const interpolationNode1 = templateStringNode.child(2);
      const interpolationNode2 = templateStringNode.child(4);
      const closeQuoteNode = templateStringNode.child(6);

      parser.setLanguage(HTML);
      const htmlRanges = [
        {
          startIndex: openQuoteNode.endIndex,
          startPosition: openQuoteNode.endPosition,
          endIndex: interpolationNode1.startIndex,
          endPosition: interpolationNode1.startPosition,
        },
        {
          startIndex: interpolationNode1.endIndex,
          startPosition: interpolationNode1.endPosition,
          endIndex: interpolationNode2.startIndex,
          endPosition: interpolationNode2.startPosition,
        },
        {
          startIndex: interpolationNode2.endIndex,
          startPosition: interpolationNode2.endPosition,
          endIndex: closeQuoteNode.startIndex,
          endPosition: closeQuoteNode.startPosition,
        },
      ];
      const htmlTree = parser.parse(sourceCode, null, {includedRanges: htmlRanges});

      assert.equal(
        htmlTree.rootNode.toString(),
        '(document (element' +
        ' (start_tag (tag_name))' +
        ' (text)' +
        ' (element (start_tag (tag_name)) (end_tag (tag_name)))' +
        ' (text)' +
        ' (end_tag (tag_name))))',
      );
      assert.deepEqual(htmlTree.getIncludedRanges(), htmlRanges);

      const divElementNode = htmlTree.rootNode.child(0);
      const helloTextNode = divElementNode.child(1);
      const bElementNode = divElementNode.child(2);
      const bStartTagNode = bElementNode.child(0);
      const bEndTagNode = bElementNode.child(1);

      assert.equal(helloTextNode.type, 'text');
      assert.equal(helloTextNode.startIndex, sourceCode.indexOf('Hello'));
      assert.equal(helloTextNode.endIndex, sourceCode.indexOf(' <b>'));

      assert.equal(bStartTagNode.type, 'start_tag');
      assert.equal(bStartTagNode.startIndex, sourceCode.indexOf('<b>'));
      assert.equal(bStartTagNode.endIndex, sourceCode.indexOf('${now()}'));

      assert.equal(bEndTagNode.type, 'end_tag');
      assert.equal(bEndTagNode.startIndex, sourceCode.indexOf('</b>'));
      assert.equal(bEndTagNode.endIndex, sourceCode.indexOf('.</div>'));
    });
  });

  describe('an included range containing mismatched positions', () => {
    it('parses the text within the range', () => {
      const sourceCode = '<div>test</div>{_ignore_this_part_}';

      parser.setLanguage(HTML);

      const endIndex = sourceCode.indexOf('{_ignore_this_part_');

      const rangeToParse = {
        startIndex: 0,
        startPosition: {row: 10, column: 12},
        endIndex,
        endPosition: {row: 10, column: 12 + endIndex},
      };

      const htmlTree = parser.parse(sourceCode, null, {includedRanges: [rangeToParse]});

      assert.deepEqual(htmlTree.getIncludedRanges()[0], rangeToParse);

      assert.equal(
        htmlTree.rootNode.toString(),
        '(document (element (start_tag (tag_name)) (text) (end_tag (tag_name))))',
      );
    });
  });

  describe('.parse', () => {
    let tree;

    beforeEach(() => {
      tree = null;
      parser.setLanguage(JavaScript);
    });

    afterEach(() => {
      if (tree) tree.delete();
    });

    it('reads from the given input', () => {
      const parts = ['first', '_', 'second', '_', 'third'];
      tree = parser.parse(() => parts.shift());
      assert.equal(tree.rootNode.toString(), '(program (expression_statement (identifier)))');
    });

    it('stops reading when the input callback return something that\'s not a string', () => {
      const parts = ['abc', 'def', 'ghi', {}, {}, {}, 'second-word', ' '];
      tree = parser.parse(() => parts.shift());
      assert.equal(
        tree.rootNode.toString(),
        '(program (expression_statement (identifier)))',
      );
      assert.equal(tree.rootNode.endIndex, 9);
      assert.equal(parts.length, 2);
    });

    it('throws an exception when the given input is not a function', () => {
      assert.throws(() => parser.parse(null), 'Argument must be a string or a function');
      assert.throws(() => parser.parse(5), 'Argument must be a string or a function');
      assert.throws(() => parser.parse({}), 'Argument must be a string or a function');
    });

    it('handles long input strings', () => {
      const repeatCount = 10000;
      const inputString = `[${Array(repeatCount).fill('0').join(',')}]`;

      tree = parser.parse(inputString);
      assert.equal(tree.rootNode.type, 'program');
      assert.equal(tree.rootNode.firstChild.firstChild.namedChildCount, repeatCount);
    }).timeout(5000);

    it('can use the bash parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('bash')));
      tree = parser.parse('FOO=bar echo <<EOF 2> err.txt > hello.txt \nhello${FOO}\nEOF');
      assert.equal(
        tree.rootNode.toString(),
        '(program ' +
            '(redirected_statement ' +
              'body: (command ' +
                '(variable_assignment name: (variable_name) value: (word)) ' +
                'name: (command_name (word))) ' +
              'redirect: (heredoc_redirect (heredoc_start) ' +
                'redirect: (file_redirect descriptor: (file_descriptor) destination: (word)) ' +
                'redirect: (file_redirect destination: (word)) ' +
                '(heredoc_body ' +
                  '(expansion (variable_name)) (heredoc_content)) (heredoc_end))))',
      );
    }).timeout(5000);

    it('can use the c++ parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('cpp')));
      tree = parser.parse('const char *s = R"EOF(HELLO WORLD)EOF";');
      assert.equal(
        tree.rootNode.toString(),
        '(translation_unit (declaration ' +
          '(type_qualifier) ' +
          'type: (primitive_type) ' +
          'declarator: (init_declarator ' +
            'declarator: (pointer_declarator declarator: (identifier)) ' +
            'value: (raw_string_literal delimiter: (raw_string_delimiter) (raw_string_content) (raw_string_delimiter)))))',
      );
    }).timeout(5000);

    it('can use the HTML parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('html')));
      tree = parser.parse('<div><span><custom></custom></span></div>');
      assert.equal(
        tree.rootNode.toString(),
        '(document (element (start_tag (tag_name)) (element (start_tag (tag_name)) (element (start_tag (tag_name)) (end_tag (tag_name))) (end_tag (tag_name))) (end_tag (tag_name))))',
      );
    }).timeout(5000);

    it('can use the python parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('python')));
      tree = parser.parse('class A:\n  def b():\n    c()');
      assert.equal(
        tree.rootNode.toString(),
        '(module (class_definition ' +
          'name: (identifier) ' +
          'body: (block ' +
            '(function_definition ' +
              'name: (identifier) ' +
              'parameters: (parameters) ' +
              'body: (block (expression_statement (call ' +
                'function: (identifier) ' +
                'arguments: (argument_list))))))))',
      );
    }).timeout(5000);

    it('can use the rust parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('rust')));
      tree = parser.parse('const x: &\'static str = r###"hello"###;');
      assert.equal(
        tree.rootNode.toString(),
        '(source_file (const_item ' +
          'name: (identifier) ' +
          'type: (reference_type (lifetime (identifier)) type: (primitive_type)) ' +
          'value: (raw_string_literal (string_content))))',
      );
    }).timeout(5000);

    it('can use the typescript parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('typescript')));
      tree = parser.parse('a()\nb()\n[c]');
      assert.equal(
        tree.rootNode.toString(),
        '(program ' +
          '(expression_statement (call_expression function: (identifier) arguments: (arguments))) ' +
          '(expression_statement (subscript_expression ' +
            'object: (call_expression ' +
              'function: (identifier) ' +
              'arguments: (arguments)) ' +
            'index: (identifier))))',
      );
    }).timeout(5000);

    it('can use the tsx parser', async () => {
      parser.setLanguage(await Parser.Language.load(languageURL('tsx')));
      tree = parser.parse('a()\nb()\n[c]');
      assert.equal(
        tree.rootNode.toString(),
        '(program ' +
          '(expression_statement (call_expression function: (identifier) arguments: (arguments))) ' +
          '(expression_statement (subscript_expression ' +
            'object: (call_expression ' +
              'function: (identifier) ' +
              'arguments: (arguments)) ' +
            'index: (identifier))))',
      );
    }).timeout(5000);

    it('parses only the text within the `includedRanges` if they are specified', () => {
      const sourceCode = '<% foo() %> <% bar %>';

      const start1 = sourceCode.indexOf('foo');
      const end1 = start1 + 5;
      const start2 = sourceCode.indexOf('bar');
      const end2 = start2 + 3;

      const tree = parser.parse(sourceCode, null, {
        includedRanges: [
          {
            startIndex: start1,
            endIndex: end1,
            startPosition: {row: 0, column: start1},
            endPosition: {row: 0, column: end1},
          },
          {
            startIndex: start2,
            endIndex: end2,
            startPosition: {row: 0, column: start2},
            endPosition: {row: 0, column: end2},
          },
        ],
      });

      assert.equal(
        tree.rootNode.toString(),
        '(program (expression_statement (call_expression function: (identifier) arguments: (arguments))) (expression_statement (identifier)))',
      );
    });
  });
});