first commit

liusuyi

2023-04-24 4737f1e038743ced243c9e52423404d9034d6107

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
/**
 * @fileoverview Rule to enforce a particular function style
 * @author Nicholas C. Zakas
 */
"use strict";
 
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
 
module.exports = {
    meta: {
        type: "suggestion",
 
        docs: {
            description: "enforce the consistent use of either `function` declarations or expressions",
            category: "Stylistic Issues",
            recommended: false,
            url: "https://eslint.org/docs/rules/func-style"
        },
 
        schema: [
            {
                enum: ["declaration", "expression"]
            },
            {
                type: "object",
                properties: {
                    allowArrowFunctions: {
                        type: "boolean",
                        default: false
                    }
                },
                additionalProperties: false
            }
        ],
 
        messages: {
            expression: "Expected a function expression.",
            declaration: "Expected a function declaration."
        }
    },
 
    create(context) {
 
        const style = context.options[0],
            allowArrowFunctions = context.options[1] && context.options[1].allowArrowFunctions,
            enforceDeclarations = (style === "declaration"),
            stack = [];
 
        const nodesToCheck = {
            FunctionDeclaration(node) {
                stack.push(false);
 
                if (!enforceDeclarations && node.parent.type !== "ExportDefaultDeclaration") {
                    context.report({ node, messageId: "expression" });
                }
            },
            "FunctionDeclaration:exit"() {
                stack.pop();
            },
 
            FunctionExpression(node) {
                stack.push(false);
 
                if (enforceDeclarations && node.parent.type === "VariableDeclarator") {
                    context.report({ node: node.parent, messageId: "declaration" });
                }
            },
            "FunctionExpression:exit"() {
                stack.pop();
            },
 
            ThisExpression() {
                if (stack.length > 0) {
                    stack[stack.length - 1] = true;
                }
            }
        };
 
        if (!allowArrowFunctions) {
            nodesToCheck.ArrowFunctionExpression = function() {
                stack.push(false);
            };
 
            nodesToCheck["ArrowFunctionExpression:exit"] = function(node) {
                const hasThisExpr = stack.pop();
 
                if (enforceDeclarations && !hasThisExpr && node.parent.type === "VariableDeclarator") {
                    context.report({ node: node.parent, messageId: "declaration" });
                }
            };
        }
 
        return nodesToCheck;
 
    }
};