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"use strict" ;
/ * *
* @ license
* Copyright 2017 Palantir Technologies , Inc .
*
* Licensed under the Apache License , Version 2.0 ( the "License" ) ;
* you may not use this file except in compliance with the License .
* You may obtain a copy of the License at
*
* http : //www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing , software
* distributed under the License is distributed on an "AS IS" BASIS ,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND , either express or implied .
* See the License for the specific language governing permissions and
* limitations under the License .
* /
Object . defineProperty ( exports , "__esModule" , { value : true } ) ;
var tslib _1 = require ( "tslib" ) ;
var tsutils _1 = require ( "tsutils" ) ;
var ts = require ( "typescript" ) ;
var Lint = require ( "../index" ) ;
var OPTION _SINGLE _CONCAT = "allow-single-concat" ;
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var Rule = /** @class */ ( function ( _super ) {
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tslib _1 . _ _extends ( Rule , _super ) ;
function Rule ( ) {
return _super !== null && _super . apply ( this , arguments ) || this ;
}
Rule . prototype . apply = function ( sourceFile ) {
if ( sourceFile . isDeclarationFile ) {
return [ ] ; // Not possible in a declaration file
}
var allowSingleConcat = this . ruleArguments . indexOf ( OPTION _SINGLE _CONCAT ) !== - 1 ;
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return this . applyWithFunction ( sourceFile , walk , { allowSingleConcat : allowSingleConcat } ) ;
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} ;
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/* tslint:disable:object-literal-sort-keys */
Rule . metadata = {
ruleName : "prefer-template" ,
description : "Prefer a template expression over string literal concatenation." ,
optionsDescription : ( _a = [ "\n If `" , "` is specified, then a single concatenation (`x + y`) is allowed, but not more (`x + y + z`)." ] , _a . raw = [ "\n If \\`" , "\\` is specified, then a single concatenation (\\`x + y\\`) is allowed, but not more (\\`x + y + z\\`)." ] , Lint . Utils . dedent ( _a , OPTION _SINGLE _CONCAT ) ) ,
options : {
type : "string" ,
enum : [ OPTION _SINGLE _CONCAT ] ,
} ,
optionExamples : [ true , [ true , OPTION _SINGLE _CONCAT ] ] ,
type : "style" ,
typescriptOnly : false ,
} ;
/* tslint:enable:object-literal-sort-keys */
Rule . FAILURE _STRING = "Use a template literal instead of concatenating with a string literal." ;
Rule . FAILURE _STRING _MULTILINE = "Use a multiline template literal instead of concatenating string literals with newlines." ;
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return Rule ;
} ( Lint . Rules . AbstractRule ) ) ;
exports . Rule = Rule ;
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function walk ( ctx ) {
var allowSingleConcat = ctx . options . allowSingleConcat ;
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return ts . forEachChild ( ctx . sourceFile , function cb ( node ) {
var failure = getError ( node , allowSingleConcat ) ;
if ( failure !== undefined ) {
ctx . addFailureAtNode ( node , failure ) ;
}
else {
return ts . forEachChild ( node , cb ) ;
}
} ) ;
}
function getError ( node , allowSingleConcat ) {
if ( ! isPlusExpression ( node ) ) {
return undefined ;
}
var left = node . left , right = node . right ;
var l = isStringLike ( left ) ;
var r = isStringLike ( right ) ;
if ( l && r ) {
// They're both strings.
// If they're joined by a newline, recommend a template expression instead.
// Otherwise ignore. ("a" + "b", probably writing a long newline-less string on many lines.)
return containsNewline ( left ) || containsNewline ( right ) ? Rule . FAILURE _STRING _MULTILINE : undefined ;
}
else if ( ! l && ! r ) {
// Watch out for `"a" + b + c`. Parsed as `("a" + b) + c`.
return containsAnyStringLiterals ( left ) ? Rule . FAILURE _STRING : undefined ;
}
else if ( l ) {
// `"x" + y`
return ! allowSingleConcat ? Rule . FAILURE _STRING : undefined ;
}
else {
// `? + "b"`
// If LHS consists of only string literals (as in `"a" + "b" + "c"`, allow it.)
return ! containsOnlyStringLiterals ( left ) && ( ! allowSingleConcat || isPlusExpression ( left ) ) ? Rule . FAILURE _STRING : undefined ;
}
}
function containsNewline ( node ) {
if ( node . kind === ts . SyntaxKind . TemplateExpression ) {
return node . templateSpans . some ( function ( _a ) {
var text = _a . literal . text ;
return text . includes ( "\n" ) ;
} ) ;
}
else {
return node . text . includes ( "\n" ) ;
}
}
function containsOnlyStringLiterals ( node ) {
return isPlusExpression ( node ) && isStringLike ( node . right ) && ( isStringLike ( node . left ) || containsAnyStringLiterals ( node . left ) ) ;
}
function containsAnyStringLiterals ( node ) {
return isPlusExpression ( node ) && ( isStringLike ( node . right ) || isStringLike ( node . left ) || containsAnyStringLiterals ( node . left ) ) ;
}
function isPlusExpression ( node ) {
return tsutils _1 . isBinaryExpression ( node ) && node . operatorToken . kind === ts . SyntaxKind . PlusToken ;
}
function isStringLike ( node ) {
switch ( node . kind ) {
case ts . SyntaxKind . StringLiteral :
case ts . SyntaxKind . NoSubstitutionTemplateLiteral :
case ts . SyntaxKind . TemplateExpression :
return true ;
default :
return false ;
}
}
var _a ;