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pegjs/test/unit/compiler/passes/report-incorrect-plucking.s...

53 lines
1.6 KiB
JavaScript

"use strict";
const { expect, use } = require( "chai" );
const helpers = require( "./helpers" );
const pass = require( "pegjs" ).compiler.passes.check.reportIncorrectPlucking;
use( helpers );
describe( "compiler pass |reportIncorrectPlucking|", function () {
function reports( error, edgecases ) {
it( error.slice( 0, -1 ), () => {
edgecases.forEach( grammar => expect( pass ).to.reportError( grammar, error ) );
} );
}
reports( `"@" cannot be used with an action block.`, [
`start1 = 'a' @'b' 'c' { /* empty action block */ }`,
`start2 = 'a' @('b' @'c' { /* empty action block */ })`
] );
reports( `"@" cannot be used on a semantic predicate.`, [
`start1 = 'a' @&{ /* semantic_and */ } 'c'`,
`start2 = 'a' @!{ /* semantic_not */ } 'c'`
] );
it( "allows valid plucking", function () {
expect( pass ).not.to.reportError( `
start1 = @'1' // return '1'
start2 = @'1' / @'2' // return '1' or '2'
start2 = '1' @'2' '3' // return '2'
start3 = '1' @b:'2' '3' // return '2', label "b" can be used in semantic predicates
start4 = a:'1' @b:'2' '3' // return '2', labels "a" and "b" can be used in semantic predicates
start5 = @'1' @'2' '3' // return ['1', '2']
start6 = @'1' @b:'2' '3' // return ['1', '2'], label "b" can be used in semantic predicates
start7 = a:'1' @'2' &{} // return '2' if the semantic predicate doesnt fail
` );
} );
} );