Found no return statements in callbacks of array methods JS-0042
Anti-pattern
Major
7 months ago
—
a year old
Array.prototype.map() expects a return value from arrow function
152 markdown += `\n`;
153 markdown += `|Code|Status|\n`;
154 markdown += `|---|---|\n`;
155 responses.map((response) => {156 markdown += `|${response.code}|${response.status}|\n`;
157 });
158 markdown += `\n`;Array.prototype.map() expects a return value from arrow function
120 markdown += `\n`;
121 markdown += `|Param|value|Type|\n`;
122 markdown += `|---|---|---|\n`;
123 body.formdata.map((form) => {124 markdown += `|${form.key}|${
125 form.type === "file"
126 ? form.srcArray.prototype.map() expects a return value from arrow function
89 markdown += `\n`;
90 markdown += `|Param|value|\n`;
91 markdown += `|---|---|\n`;
92 url.query.map((query) => { 93 markdown += `|${query.key}|${query.value}|\n`;
94 });
95 markdown += `\n`;Array.prototype.map() expects a return value from arrow function
66 markdown += `\n`;
67 markdown += `|Parameter|Value|Description|\n`;
68 markdown += `|---|---|---|\n`;
69 data.header.map((header) => { 70 markdown += `|${header.key}|${header.value}|${header.description}|\n`;
71 });
72 return markdown;Array.prototype.map() expects a return value from arrow function
44 markdown += `|Param|value|Type|\n`;
45 markdown += `|---|---|---|\n`;
46
47 data.bearer.map((auth) => { 48 markdown += `|${auth.key}|${auth.value}|${auth.type}|\n`;
49 });
50 markdown += `\n`;
Description
Array has several methods for filtering, mapping, and folding.
If we forget to write return statement in a callback of those, it's probably a mistake.
If you don't want to use a return or don't need the returned results, consider using .forEach instead.
Bad Practice
const indexMap = myArray.reduce(function(memo, item, index) {
memo[item] = index;
}, {});
const foo = Array.from(nodes, function(node) {
if (node.tagName === "DIV") {
return true;
}
});
const bar = foo.filter(function(x) {
if (x) {
return true;
} else {
return;
}
});
Recommended
const indexMap = myArray.reduce(function(memo, item, index) {
memo[item] = index;
return memo;
}, {});
const foo = Array.from(nodes, function(node) {
if (node.tagName === "DIV") {
return true;
}
return false;
});
const bar = foo.map(node => node.getAttribute("id"));