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Change generate() function interface to be same as parse(). Change pa…
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…rse() to parse headers by default
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@koresar
koresar committed Mar 17, 2021
1 parent cea1cea commit bb5833c
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Showing 2 changed files with 70 additions and 54 deletions.
80 changes: 49 additions & 31 deletions src/lil-csv.js
View file
Original file line number Diff line number Diff line change
@@ -1,11 +1,11 @@
export const isString = (f) => typeof f === "string";
export const isNumber = (f) => typeof f === "number";
export const isBoolean = (f) => typeof f === "boolean";
export const isDate = (o) => o instanceof Date && !isNaN(o.valueOf());

export const isFunction = (f) => typeof f === "function";

export function parse(str, { header = false, escapeChar = "\\" } = {}) {
export const isString = (v) => typeof v === "string";
export const isNumber = (v) => typeof v === "number";
export const isBoolean = (v) => typeof v === "boolean";
export const isDate = (v) => v instanceof Date && !isNaN(v.valueOf());
export const isObject = (v) => v && typeof v === "object";
export const isFunction = (v) => typeof v === "function";

export function parse(str, { header = true, escapeChar = "\\" } = {}) {
const entries = [];
let quote = false; // 'true' means we're inside a quoted field
let newRow = false; // 'true' means we need to finish this line
Expand Down Expand Up @@ -85,33 +85,51 @@ export function parse(str, { header = false, escapeChar = "\\" } = {}) {
});
}

export function generate({ header, rows, lineTerminator = "\n", escapeChar = "\\" }) {
if (!header) header = "";
else {
if (Array.isArray(header)) header = header.map((h) => (isString(h) && h.includes(",") ? `"${h}"` : h)).join();
if (!isString(header)) throw new Error("Header must be either string or array of strings");
header = header + lineTerminator;
export function generate(rows, { header, lineTerminator = "\n", escapeChar = "\\" } = {}) {
if (header) {
if (isBoolean(header)) {
header = Array.from(rows.reduce((all, row) => new Set([...all, ...Object.keys(row)]), new Set()));
} else if (Array.isArray(header)) {
if (!header.every(isString)) throw new Error("If header is array all items must be strings");
} else if (isObject(header)) {
header = Object.entries(header)
.filter(([k, v]) => v)
.map(([k]) => k);
} else {
throw new Error("Header must be either boolean, or array, or object");
}

header = header.map((h) => {
h = h.replace(/"/g, escapeChar + '"');
return h.includes(",") ? `"${h}"` : h;
});
}

function valueToString(v) {
if (v == null || v === "" || !((isNumber(v) && !isNaN(v)) || isString(v) || isDate(v) || isBoolean(v)))
return ""; // ignore bad data

v = isDate(v) ? v.toISOString() : String(v); // convert any kind of value to string
v = v.replace(/"/g, escapeChar + '"'); // Escape quote character
if (v.includes(",")) v = '"' + v + '"'; // Add quotes if value has commas
return v;
}

const textHeader = header ? header.join() + lineTerminator : "";
return (
header +
textHeader +
rows
.map((row) =>
row
.map((v) => {
if (
v == null ||
v === "" ||
!((isNumber(v) && !isNaN(v)) || isString(v) || isDate(v) || isBoolean(v))
)
return ""; // ignore bad data
v = isDate(v) ? v.toISOString() : String(v); // convert any kind of value to string
v = v.replace(/"/g, escapeChar + '"'); // Escape quote character
if (v.includes(",")) v = '"' + v + '"'; // Add quotes if value has commas
return v;
})
.join()
)
.map((row, i) => {
if (Array.isArray(row)) {
if (header && row.length !== header.length)
throw new Error(`Each row array must have exactly ${header.length} items`);
return row.map(valueToString).join();
}
if (isObject(row)) {
return header.map((h) => valueToString(row[h])).join();
}
throw new Error(`Row ${i} must be either array or object`);
})
.join(lineTerminator)
);
}
44 changes: 21 additions & 23 deletions test/lil-csv.test.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ describe("parse", () => {
it("should parse", () => {
const text = `Column,Second Column,else\rhere, we go ,false\r\n"with,comma","with \\" escaped quotes",123\n"",empty,
`;
const rows = parse(text);
const rows = parse(text, { header: false });
assert.deepStrictEqual(rows, [
["Column", "Second Column", "else"],
["here", " we go ", "false"],
Expand All @@ -17,7 +17,7 @@ describe("parse", () => {

it("should parse funky data", () => {
const text = `"Column","Second" Column,Third "Column",Middle "quotes" column`;
const rows = parse(text);
const rows = parse(text, { header: false });
assert.deepStrictEqual(rows, [["Column", "Second Column", `Third Column`, `Middle quotes column`]]);
});

Expand Down Expand Up @@ -61,14 +61,13 @@ describe("parse", () => {
describe("generate", () => {
it("should generate and parse back", () => {
const rows = parse(
generate({
rows: [
[`Column`, `Second Column`, `else`],
["here", " we go ", "false"],
["with,comma", 'with " escaped quotes', "123"],
["", "empty", ""],
],
})
generate([
[`Column`, `Second Column`, `else`],
["here", " we go ", "false"],
["with,comma", 'with " escaped quotes', "123"],
["", "empty", ""],
]),
{ header: false }
);
assert.deepStrictEqual(rows, [
[`Column`, `Second Column`, `else`],
Expand All @@ -79,14 +78,14 @@ describe("generate", () => {
});

it("should generate with header", () => {
const rows = generate({
header: [`Column`, `Second Column`, `else`],
rows: [
const rows = generate(
[
["here", " we go ", "false"],
["with,comma", 'with " escaped quotes', "123"],
["", "empty", ""],
],
});
{ header: [`Column`, `Second Column`, `else`] }
);
assert.deepStrictEqual(
rows,
`Column,Second Column,else
Expand All @@ -97,9 +96,8 @@ here, we go ,false
});

it("should auto format some primitives", () => {
const rows = generate({
const rows = generate([[new Date("2020-12-12"), 123.123, false]], {
header: [`Column`, `Second Column`, `else`],
rows: [[new Date("2020-12-12"), 123.123, false]],
});
assert.deepStrictEqual(
rows,
Expand All @@ -109,22 +107,22 @@ here, we go ,false
});

it("should ignore bad data", () => {
const rows = generate({
rows: [[null, undefined, {}, [], () => {}, NaN, "", new Map(), new Set()]],
});
const rows = generate([[null, undefined, {}, [], () => {}, NaN, "", new Map(), new Set()]]);
assert.deepStrictEqual(rows, `,,,,,,,,`);
});
});

describe("generate + parse", () => {
it("should work on fully customised options", () => {
const text = generate({
header: [`A string`, `num`, `bool`, `date`, `date of birth`, `bad data`, `skip this`, `skip this too`],
rows: [
const text = generate(
[
["my str", -123.123, false, new Date("2020-12-12"), "1999-09-09", {}, "whatever", ""],
[-1, "not number", "False", new Date("invalid date"), "bad DOB", [], "whatever", ""],
],
});
{
header: [`A string`, `num`, `bool`, `date`, `date of birth`, `bad data`, `skip this`, `skip this too`],
}
);
const data = parse(text, {
header: {
"A string": { jsonName: "stringX" },
Expand Down

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