Decouple getCreationDates & getModificationDates from Obsidian datatypes

Make it easier to maintain and test

src/creatmodchartcalculation.ts

@@ -30,8 +30,8 @@ export function findEarliestModifiedFile<T extends FileInterface>(files: T[]): T
 }  
 
 
-export function findEarliestDateFile(files: TFile[]): TFile {
-	let earliestCreatedFile: TFile = files[0];
+export function findEarliestDateFile<T extends FileInterface>(files: T[]): T {
+	let earliestCreatedFile: T = files[0];
 	for (const file of files) {
 		if (file.stat.ctime < earliestCreatedFile.stat.ctime) {
 			earliestCreatedFile = file;
@@ -53,25 +53,21 @@ export function monthsBetween(startMonth: Date, endMonth: Date): number {
 }
 
 
-export function getCreationDates(files: TFile[]): Array<Date> {
+export function getCreationDates<T extends FileInterface>(files: T[]): Array<Date> {
 	const creationDates: Array<Date> = [];
-
 	for (const file of files) {
 		creationDates.push(new Date(file.stat.ctime));
 	}
-
 	return creationDates;
 }
 
 
-export function getModificationDates(files: TFile[]): Array<Date> {
-	const creationDates: Array<Date> = [];
-
+export function getModificationDates<T extends FileInterface>(files: T[]): Array<Date> {
+	const modificationDates: Array<Date> = [];
 	for (const file of files) {
-		creationDates.push(new Date(file.stat.mtime));
+		modificationDates.push(new Date(file.stat.mtime));
 	}
-
-	return creationDates;
+	return modificationDates;
 }
 
 

tests/creatmodchartcalculation.test.ts

@@ -52,6 +52,24 @@ describe('findEarliestModifiedFile', () => {
 	});
 });
 
+describe('findEarliestDateFile', () => {
+	it('should return the file with the earliest date for creation or modification time', () => {
+		const result = findEarliestDateFile(files);
+		expect(result).toEqual(files[1]);
+	});
+
+	it('should handle an empty array', () => {
+		const result = findEarliestDateFile([]);
+		expect(result).toBeUndefined();
+	});
+
+	it('should handle a single element array', () => {
+		const singleFile = [files[0]];
+		const result = findEarliestDateFile(singleFile);
+		expect(result).toEqual(files[0]);
+	});
+});
+
 describe('monthsBetween', () => {
   it('should return how many month are between March 22 and July 23', () => {
   const actual = monthsBetween(new Date(2022,3), new Date(2023,6));
@@ -73,6 +91,50 @@ describe('monthsBetween', () => {
 });
 
 
+describe('getCreationDates', () => {
+	it('should return an array of creation dates', () => {
+		const result = getCreationDates(files);
+		expect(result).toEqual([
+			new Date(1625234672000),
+			new Date(1625233672000),
+			new Date(1625235672000)
+		]);
+	});
+
+	it('should handle an empty array', () => {
+		const result = getCreationDates([]);
+		expect(result).toEqual([]);
+	});
+
+	it('should handle a single element array', () => {
+		const singleFile = [files[0]];
+		const result = getCreationDates(singleFile);
+		expect(result).toEqual([new Date(1625234672000)]);
+	});
+});
+
+describe('getModificationDates', () => {
+	it('should return an array of modification dates', () => {
+		const result = getModificationDates(files);
+		expect(result).toEqual([
+			new Date(1625234672000),
+			new Date(1625233672000),
+			new Date(1625235672000)
+		]);
+	});
+
+	it('should handle an empty array', () => {
+		const result = getModificationDates([]);
+		expect(result).toEqual([]);
+	});
+
+	it('should handle a single element array', () => {
+		const singleFile = [files[0]];
+		const result = getModificationDates(singleFile);
+		expect(result).toEqual([new Date(1625234672000)]);
+	});
+});
+
 describe('createChartFormat', () => {
   it('should return chart full length', () => {
   const actual = createChartFormat("Jan 22, Feb 22, Mar 22, April 22", "0, 1, 2, 3", 0);