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

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

describe('Query', () => {
  let parser; let tree; let query;

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

  beforeEach(() => {
    parser = new Parser().setLanguage(JavaScript);
  });

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

  describe('construction', () => {
    it('throws an error on invalid patterns', () => {
      assert.throws(() => {
        JavaScript.query('(function_declaration wat)');
      }, 'Bad syntax at offset 22: \'wat)\'...');
      assert.throws(() => {
        JavaScript.query('(non_existent)');
      }, 'Bad node name \'non_existent\'');
      assert.throws(() => {
        JavaScript.query('(a)');
      }, 'Bad node name \'a\'');
      assert.throws(() => {
        JavaScript.query('(function_declaration non_existent:(identifier))');
      }, 'Bad field name \'non_existent\'');
      assert.throws(() => {
        JavaScript.query('(function_declaration name:(statement_block))');
      }, 'Bad pattern structure at offset 22: \'name:(statement_block))\'');
    });

    it('throws an error on invalid predicates', () => {
      assert.throws(() => {
        JavaScript.query('((identifier) @abc (#eq? @ab hi))');
      }, 'Bad capture name @ab');
      assert.throws(() => {
        JavaScript.query('((identifier) @abc (#eq? @ab hi))');
      }, 'Bad capture name @ab');
      assert.throws(() => {
        JavaScript.query('((identifier) @abc (#eq?))');
      }, 'Wrong number of arguments to `#eq?` predicate. Expected 2, got 0');
      assert.throws(() => {
        JavaScript.query('((identifier) @a (#eq? @a @a @a))');
      }, 'Wrong number of arguments to `#eq?` predicate. Expected 2, got 3');
    });
  });

  describe('.matches', () => {
    it('returns all of the matches for the given query', () => {
      tree = parser.parse('function one() { two(); function three() {} }');
      query = JavaScript.query(`
        (function_declaration name: (identifier) @fn-def)
        (call_expression function: (identifier) @fn-ref)
      `);
      const matches = query.matches(tree.rootNode);
      assert.deepEqual(formatMatches(matches), [
        {pattern: 0, captures: [{name: 'fn-def', text: 'one'}]},
        {pattern: 1, captures: [{name: 'fn-ref', text: 'two'}]},
        {pattern: 0, captures: [{name: 'fn-def', text: 'three'}]},
      ]);
    });

    it('can search in a specified ranges', () => {
      tree = parser.parse('[a, b,\nc, d,\ne, f,\ng, h]');
      query = JavaScript.query('(identifier) @element');
      const matches = query.matches(
        tree.rootNode,
        {
          startPosition: {row: 1, column: 1},
          endPosition: {row: 3, column: 1},
        },
      );
      assert.deepEqual(formatMatches(matches), [
        {pattern: 0, captures: [{name: 'element', text: 'd'}]},
        {pattern: 0, captures: [{name: 'element', text: 'e'}]},
        {pattern: 0, captures: [{name: 'element', text: 'f'}]},
        {pattern: 0, captures: [{name: 'element', text: 'g'}]},
      ]);
    });

    it('handles predicates that compare the text of capture to literal strings', () => {
      tree = parser.parse(`
        giraffe(1, 2, []);
        helment([false]);
        goat(false);
        gross(3, []);
        hiccup([]);
        gaff(5);
      `);

      // Find all calls to functions beginning with 'g', where one argument
      // is an array literal.
      query = JavaScript.query(`
        (call_expression
          function: (identifier) @name
          arguments: (arguments (array))
          (#match? @name "^g"))
      `);

      const matches = query.matches(tree.rootNode);
      assert.deepEqual(formatMatches(matches), [
        {pattern: 0, captures: [{name: 'name', text: 'giraffe'}]},
        {pattern: 0, captures: [{name: 'name', text: 'gross'}]},
      ]);
    });

    it('handles multiple matches where the first one is filtered', () => {
      tree = parser.parse(`
        const a = window.b;
      `);

      query = JavaScript.query(`
        ((identifier) @variable.builtin
          (#match? @variable.builtin "^(arguments|module|console|window|document)$")
          (#is-not? local))
      `);

      const matches = query.matches(tree.rootNode);
      assert.deepEqual(formatMatches(matches), [
        {pattern: 0, captures: [{name: 'variable.builtin', text: 'window'}]},
      ]);
    });
  });

  describe('.captures', () => {
    it('returns all of the captures for the given query, in order', () => {
      tree = parser.parse(`
        a({
          bc: function de() {
            const fg = function hi() {}
          },
          jk: function lm() {
            const no = function pq() {}
          },
        });
      `);
      query = JavaScript.query(`
        (pair
          key: _ @method.def
          (function_expression
            name: (identifier) @method.alias))

        (variable_declarator
          name: _ @function.def
          value: (function_expression
            name: (identifier) @function.alias))

        ":" @delimiter
        "=" @operator
      `);

      const captures = query.captures(tree.rootNode);
      assert.deepEqual(formatCaptures(captures), [
        {name: 'method.def', text: 'bc'},
        {name: 'delimiter', text: ':'},
        {name: 'method.alias', text: 'de'},
        {name: 'function.def', text: 'fg'},
        {name: 'operator', text: '='},
        {name: 'function.alias', text: 'hi'},
        {name: 'method.def', text: 'jk'},
        {name: 'delimiter', text: ':'},
        {name: 'method.alias', text: 'lm'},
        {name: 'function.def', text: 'no'},
        {name: 'operator', text: '='},
        {name: 'function.alias', text: 'pq'},
      ]);
    });

    it('handles conditions that compare the text of capture to literal strings', () => {
      tree = parser.parse(`
        lambda
        panda
        load
        toad
        const ab = require('./ab');
        new Cd(EF);
      `);

      query = JavaScript.query(`
        ((identifier) @variable
         (#not-match? @variable "^(lambda|load)$"))

        ((identifier) @function.builtin
         (#eq? @function.builtin "require"))

        ((identifier) @constructor
         (#match? @constructor "^[A-Z]"))

        ((identifier) @constant
         (#match? @constant "^[A-Z]{2,}$"))
      `);

      const captures = query.captures(tree.rootNode);
      assert.deepEqual(formatCaptures(captures), [
        {name: 'variable', text: 'panda'},
        {name: 'variable', text: 'toad'},
        {name: 'variable', text: 'ab'},
        {name: 'variable', text: 'require'},
        {name: 'function.builtin', text: 'require'},
        {name: 'variable', text: 'Cd'},
        {name: 'constructor', text: 'Cd'},
        {name: 'variable', text: 'EF'},
        {name: 'constructor', text: 'EF'},
        {name: 'constant', text: 'EF'},
      ]);
    });

    it('handles conditions that compare the text of capture to each other', () => {
      tree = parser.parse(`
        ab = abc + 1;
        def = de + 1;
        ghi = ghi + 1;
      `);

      query = JavaScript.query(`
        (
          (assignment_expression
            left: (identifier) @id1
            right: (binary_expression
              left: (identifier) @id2))
          (#eq? @id1 @id2)
        )
      `);

      const captures = query.captures(tree.rootNode);
      assert.deepEqual(formatCaptures(captures), [
        {name: 'id1', text: 'ghi'},
        {name: 'id2', text: 'ghi'},
      ]);
    });

    it('handles patterns with properties', () => {
      tree = parser.parse(`a(b.c);`);
      query = JavaScript.query(`
        ((call_expression (identifier) @func)
         (#set! foo)
         (#set! bar baz))

        ((property_identifier) @prop
         (#is? foo)
         (#is-not? bar baz))
      `);

      const captures = query.captures(tree.rootNode);
      assert.deepEqual(formatCaptures(captures), [
        {name: 'func', text: 'a', setProperties: {foo: null, bar: 'baz'}},
        {
          name: 'prop',
          text: 'c',
          assertedProperties: {foo: null},
          refutedProperties: {bar: 'baz'},
        },
      ]);
      assert.ok(!query.didExceedMatchLimit());
    });

    it('detects queries with too many permutations to track', () => {
      tree = parser.parse(`
        [
          hello, hello, hello, hello, hello, hello, hello, hello, hello, hello,
          hello, hello, hello, hello, hello, hello, hello, hello, hello, hello,
          hello, hello, hello, hello, hello, hello, hello, hello, hello, hello,
          hello, hello, hello, hello, hello, hello, hello, hello, hello, hello,
          hello, hello, hello, hello, hello, hello, hello, hello, hello, hello,
        ];
      `);

      query = JavaScript.query(`
        (array (identifier) @pre (identifier) @post)
      `);

      query.captures(tree.rootNode, {matchLimit: 32});
      assert.ok(query.didExceedMatchLimit());
    });

    it('handles quantified captures properly', () => {
      let captures;

      tree = parser.parse(`
        /// foo
        /// bar
        /// baz
      `);

      query = JavaScript.query(`
        (
          (comment)+ @foo
          (#any-eq? @foo "/// foo")
        )
      `);

      const expectCount = (tree, queryText, expectedCount) => {
        query = JavaScript.query(queryText);
        captures = query.captures(tree.rootNode);
        assert.equal(captures.length, expectedCount);
      };

      expectCount(
        tree,
        `((comment)+ @foo (#any-eq? @foo "/// foo"))`,
        3,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#eq? @foo "/// foo"))`,
        0,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#any-not-eq? @foo "/// foo"))`,
        3,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#not-eq? @foo "/// foo"))`,
        0,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#match? @foo "^/// foo"))`,
        0,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#any-match? @foo "^/// foo"))`,
        3,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#not-match? @foo "^/// foo"))`,
        0,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#not-match? @foo "fsdfsdafdfs"))`,
        3,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#any-not-match? @foo "^///"))`,
        0,
      );

      expectCount(
        tree,
        `((comment)+ @foo (#any-not-match? @foo "^/// foo"))`,
        3,
      );
    });
  });

  describe('.predicatesForPattern(index)', () => {
    it('returns all of the predicates as objects', () => {
      query = JavaScript.query(`
        (
          (binary_expression
            left: (identifier) @a
            right: (identifier) @b)
          (#something? @a @b)
          (#match? @a "c")
          (#something-else? @a "A" @b "B")
        )

        ((identifier) @c
         (#hello! @c))

        "if" @d
      `);

      assert.deepEqual(query.predicatesForPattern(0), [
        {
          operator: 'something?',
          operands: [
            {type: 'capture', name: 'a'},
            {type: 'capture', name: 'b'},
          ],
        },
        {
          operator: 'something-else?',
          operands: [
            {type: 'capture', name: 'a'},
            {type: 'string', value: 'A'},
            {type: 'capture', name: 'b'},
            {type: 'string', value: 'B'},
          ],
        },
      ]);
      assert.deepEqual(query.predicatesForPattern(1), [
        {
          operator: 'hello!',
          operands: [{type: 'capture', name: 'c'}],
        },
      ]);
      assert.deepEqual(query.predicatesForPattern(2), []);
    });
  });

  describe('.disableCapture', () => {
    it('disables a capture', () => {
      const query = JavaScript.query(`
        (function_declaration
          (identifier) @name1 @name2 @name3
          (statement_block) @body1 @body2)
      `);

      const source = 'function foo() { return 1; }';
      const tree = parser.parse(source);

      let matches = query.matches(tree.rootNode);
      assert.deepEqual(formatMatches(matches), [
        {
          pattern: 0,
          captures: [
            {name: 'name1', text: 'foo'},
            {name: 'name2', text: 'foo'},
            {name: 'name3', text: 'foo'},
            {name: 'body1', text: '{ return 1; }'},
            {name: 'body2', text: '{ return 1; }'},
          ],
        },
      ]);

      // disabling captures still works when there are multiple captures on a
      // single node.
      query.disableCapture('name2');
      matches = query.matches(tree.rootNode);
      assert.deepEqual(formatMatches(matches), [
        {
          pattern: 0,
          captures: [
            {name: 'name1', text: 'foo'},
            {name: 'name3', text: 'foo'},
            {name: 'body1', text: '{ return 1; }'},
            {name: 'body2', text: '{ return 1; }'},
          ],
        },
      ]);
    });
  });

  describe('Set a timeout', () =>
    it('returns less than the expected matches', () => {
      tree = parser.parse('function foo() while (true) { } }\n'.repeat(1000));
      query = JavaScript.query('(function_declaration name: (identifier) @function)');
      const matches = query.matches(tree.rootNode, { timeoutMicros: 1000 });
      assert.isBelow(matches.length, 1000);
      const matches2 = query.matches(tree.rootNode, { timeoutMicros: 0 });
      assert.equal(matches2.length, 1000);
    })
  );
});

function formatMatches(matches) {
  return matches.map(({pattern, captures}) => ({
    pattern,
    captures: formatCaptures(captures),
  }));
}

function formatCaptures(captures) {
  return captures.map((c) => {
    const node = c.node;
    delete c.node;
    c.text = node.text;
    return c;
  });
}