feat: simplify nested tables (#46)

Co-authored-by: Cynthia <[email protected]>

Author: penalosa

src/stringify.ts

@@ -130,14 +130,14 @@ function stringifyArrayTable (array: any[], key: string, depth: number, numberAs
 	let res = ''
 	for (let i = 0; i < array.length; i++) {
 		res += `[[${key}]]\n`
-		res += stringifyTable(array[i], key, depth, numberAsFloat)
-		res += '\n\n'
+		res += stringifyTable(0, array[i], key, depth, numberAsFloat)
+		res += '\n'
 	}
 
 	return res
 }
 
-function stringifyTable (obj: any, prefix: string, depth: number, numberAsFloat: boolean) {
+function stringifyTable (tableKey: string | 0, obj: any, prefix: string, depth: number, numberAsFloat: boolean) {
 	if (depth === 0) {
 		throw new Error('Could not stringify the object: maximum object depth exceeded')
 	}
@@ -160,9 +160,8 @@ function stringifyTable (obj: any, prefix: string, depth: number, numberAsFloat:
 				tables += stringifyArrayTable(obj[k], prefix ? `${prefix}.${key}` : key, depth - 1, numberAsFloat)
 			} else if (type === 'object') {
 				let tblKey = prefix ? `${prefix}.${key}` : key
-				tables += `[${tblKey}]\n`
-				tables += stringifyTable(obj[k], tblKey, depth - 1, numberAsFloat)
-				tables += '\n\n'
+				let table = stringifyTable(tblKey, obj[k], tblKey, depth - 1, numberAsFloat)
+				if (table) tables += table + '\n'
 			} else {
 				preamble += key
 				preamble += ' = '
@@ -172,7 +171,12 @@ function stringifyTable (obj: any, prefix: string, depth: number, numberAsFloat:
 		}
 	}
 
-	return `${preamble}\n${tables}`.trim()
+	if (tableKey && (preamble || !tables)) // Create table only if necessary
+		preamble = preamble ? `[${tableKey}]\n${preamble}` : `[${tableKey}]`
+
+	return preamble && tables
+		? `${preamble}\n${tables}`
+		: preamble || tables
 }
 
 export function stringify (
@@ -183,5 +187,5 @@ export function stringify (
 		throw new TypeError('stringify can only be called with an object')
 	}
 
-	return stringifyTable(obj, '', maxDepth, numbersAsFloat)
+	return stringifyTable(0, obj, '', maxDepth, numbersAsFloat)
 }

test/stringify.test.ts

@@ -154,6 +154,37 @@ c = 2
 	expect(stringify({ a: { b: 1, c: 2 }, d: 3 }).trim()).toBe(expected)
 })
 
+it('stringifies nested tables and handles top-level keys', () => {
+	const expected = `
+d = 3
+
+[a.b]
+b = 1
+c = 2
+`.trim()
+
+	expect(stringify({ a: {b: { b: 1, c: 2 },  }, d: 3}).trim()).toBe(expected)
+})
+
+it("stringifies empty tables with no gaps", () => {
+	const expected = `
+[animal]
+[fruit.apple]
+[fruit.orange]
+`.trim();
+
+	expect(
+		stringify({
+			animal: {},
+			fruit: {
+				apple: {},
+				orange: {},
+			},
+		}).trim()
+	).toBe(expected);
+});
+
+
 it('stringifies tables contained in arrays', () => {
 	const expected = `
 a = [ 1, { b = 2, c = 3 }, 4 ]
@@ -176,6 +207,59 @@ c = 4
 	expect(stringify({ a: [ { b: 1, c: 2 }, { b: 3, c: 4 } ] }).trim()).toBe(expected)
 })
 
+it("stringifies nested arrays of tables", () => {
+	const expected = `
+[[a.b]]
+b = 1
+c = 2
+
+[[a.b]]
+b = 3
+c = 4
+`.trim();
+
+	expect(
+		stringify({
+			a: {
+				b: [
+					{ b: 1, c: 2 },
+					{ b: 3, c: 4 },
+				],
+			},
+		}).trim()
+	).toBe(expected);
+});
+
+it("stringifies nested arrays of tables with top level keys", () => {
+	const expected = `
+key = "hello"
+
+[a]
+key = "hello"
+
+[[a.b]]
+b = 1
+c = 2
+
+[[a.b]]
+b = 3
+c = 4
+`.trim();
+
+	expect(
+		stringify({
+			key: "hello",
+			a: {
+				key: "hello",
+				b: [
+					{ b: 1, c: 2 },
+					{ b: 3, c: 4 },
+				],
+			},
+		}).trim()
+	).toBe(expected);
+});
+
 it('does not produce invalid keys', () => {
 	const expected = `
 test-key123_ = 1