eslint/tests/lib/rules/utils/fix-tracker.js

   1 /**
   2  * @fileoverview Tests for FixTracker.
   3  * @author Alan Pierce
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const assert = require("chai").assert,
  12     espree = require("espree"),
  13     FixTracker = require("../../../../lib/rules/utils/fix-tracker"),
  14     ruleFixer = require("../../../../lib/linter/rule-fixer"),
  15     { SourceCode } = require("../../../../lib/source-code"),
  16     Traverser = require("../../../../lib/shared/traverser");
  17
  18 //------------------------------------------------------------------------------
  19 // Helpers
  20 //------------------------------------------------------------------------------
  21
  22 const DEFAULT_CONFIG = {
  23     ecmaVersion: 6,
  24     comment: true,
  25     tokens: true,
  26     range: true,
  27     loc: true
  28 };
  29
  30 /**
  31  * Create a SourceCode instance from the given code. Also add parent pointers in
  32  * the AST so that parent traversals will work.
  33  * @param {string} text The text of the code.
  34  * @returns {SourceCode} The SourceCode.
  35  */
  36 function createSourceCode(text) {
  37     const ast = espree.parse(text, DEFAULT_CONFIG);
  38
  39     Traverser.traverse(ast, {
  40         enter(node, parent) {
  41             node.parent = parent;
  42         }
  43     });
  44
  45     return new SourceCode(text, ast);
  46 }
  47
  48 //------------------------------------------------------------------------------
  49 // Tests
  50 //------------------------------------------------------------------------------
  51
  52 describe("FixTracker", () => {
  53     describe("replaceTextRange", () => {
  54         it("should expand to include an explicitly retained range", () => {
  55             const sourceCode = createSourceCode("var foo = +bar;");
  56             const result = new FixTracker(ruleFixer, sourceCode)
  57                 .retainRange([4, 14])
  58                 .replaceTextRange([10, 11], "-");
  59
  60             assert.deepStrictEqual(result, {
  61                 range: [4, 14],
  62                 text: "foo = -bar"
  63             });
  64         });
  65
  66         it("ignores a retained range that's smaller than the replaced range", () => {
  67             const sourceCode = createSourceCode("abcdefghij");
  68             const result = new FixTracker(ruleFixer, sourceCode)
  69                 .retainRange([5, 7])
  70                 .replaceTextRange([4, 8], "123");
  71
  72             assert.deepStrictEqual(result, {
  73                 range: [4, 8],
  74                 text: "123"
  75             });
  76         });
  77
  78         it("allows an unspecified retained range", () => {
  79             const sourceCode = createSourceCode("abcdefghij");
  80             const result = new FixTracker(ruleFixer, sourceCode)
  81                 .replaceTextRange([4, 8], "123");
  82
  83             assert.deepStrictEqual(result, {
  84                 range: [4, 8],
  85                 text: "123"
  86             });
  87         });
  88     });
  89
  90     describe("remove", () => {
  91         it("should expand to include an explicitly retained range", () => {
  92             const sourceCode = createSourceCode("a = b + +c");
  93             const result = new FixTracker(ruleFixer, sourceCode)
  94                 .retainRange([4, 10])
  95                 .remove(sourceCode.ast.tokens[4]);
  96
  97             assert.deepStrictEqual(result, {
  98                 range: [4, 10],
  99                 text: "b + c"
 100             });
 101         });
 102     });
 103
 104     describe("retainEnclosingFunction", () => {
 105         it("handles a normal enclosing function", () => {
 106             const sourceCode = createSourceCode("f = function() { return x; }");
 107             const xNode = sourceCode.ast.body[0].expression.right.body.body[0].argument;
 108             const result = new FixTracker(ruleFixer, sourceCode)
 109                 .retainEnclosingFunction(xNode)
 110                 .replaceTextRange(xNode.range, "y");
 111
 112             assert.deepStrictEqual(result, {
 113                 range: [4, 28],
 114                 text: "function() { return y; }"
 115             });
 116         });
 117
 118         it("handles the case when there is no enclosing function", () => {
 119             const sourceCode = createSourceCode("const a = b;");
 120             const bNode = sourceCode.ast.body[0].declarations[0].init;
 121             const result = new FixTracker(ruleFixer, sourceCode)
 122                 .retainEnclosingFunction(bNode)
 123                 .replaceTextRange(bNode.range, "c");
 124
 125             assert.deepStrictEqual(result, {
 126                 range: [0, 12],
 127                 text: "const a = c;"
 128             });
 129         });
 130     });
 131
 132     describe("retainSurroundingTokens", () => {
 133         it("handles a change to a binary operator", () => {
 134             const sourceCode = createSourceCode("const i = j + k;");
 135             const plusToken = sourceCode.ast.tokens[4];
 136             const result = new FixTracker(ruleFixer, sourceCode)
 137                 .retainSurroundingTokens(plusToken)
 138                 .replaceTextRange(plusToken.range, "*");
 139
 140             assert.deepStrictEqual(result, {
 141                 range: [10, 15],
 142                 text: "j * k"
 143             });
 144         });
 145     });
 146 });