diff --git a/src/lib/utils/game.ts b/src/lib/utils/game.ts
index ce7cf1b..979d64d 100644
--- a/src/lib/utils/game.ts
+++ b/src/lib/utils/game.ts
@@ -79,7 +79,7 @@ export function getNextGradeMessage(numGuesses: number): string {
 }
 
 export function toOrdinal(n: number): string {
-	if (n >= 11 && n <= 13) {
+	if (n % 100 >= 11 && n % 100 <= 13) {
 		return `${n}th`;
 	}
 	const mod = n % 10;
diff --git a/tests/bible.test.ts b/tests/bible.test.ts
new file mode 100644
index 0000000..759e9ed
--- /dev/null
+++ b/tests/bible.test.ts
@@ -0,0 +1,234 @@
+import { describe, test, expect } from "bun:test";
+import {
+	getBookById,
+	getBookByNumber,
+	getBooksByTestament,
+	getBooksBySection,
+	isAdjacent,
+	bookNumberToId,
+	bookIdToNumber,
+	bibleBooks,
+} from "$lib/server/bible";
+
+describe("bibleBooks data integrity", () => {
+	test("contains exactly 66 books", () => {
+		expect(bibleBooks).toHaveLength(66);
+	});
+
+	test("order numbers are 1 through 66 with no gaps or duplicates", () => {
+		const orders = bibleBooks.map((b) => b.order).sort((a, b) => a - b);
+		for (let i = 0; i < 66; i++) {
+			expect(orders[i]).toBe(i + 1);
+		}
+	});
+
+	test("book IDs are unique", () => {
+		const ids = bibleBooks.map((b) => b.id);
+		const unique = new Set(ids);
+		expect(unique.size).toBe(66);
+	});
+
+	test("every book has a non-empty name", () => {
+		for (const book of bibleBooks) {
+			expect(book.name.length).toBeGreaterThan(0);
+		}
+	});
+
+	test("Old Testament has 39 books", () => {
+		expect(bibleBooks.filter((b) => b.testament === "old")).toHaveLength(39);
+	});
+
+	test("New Testament has 27 books", () => {
+		expect(bibleBooks.filter((b) => b.testament === "new")).toHaveLength(27);
+	});
+
+	test("Genesis is first and Revelation is last", () => {
+		const sorted = [...bibleBooks].sort((a, b) => a.order - b.order);
+		expect(sorted[0].id).toBe("GEN");
+		expect(sorted[65].id).toBe("REV");
+	});
+
+	test("Matthew is the first New Testament book", () => {
+		const nt = bibleBooks
+			.filter((b) => b.testament === "new")
+			.sort((a, b) => a.order - b.order);
+		expect(nt[0].id).toBe("MAT");
+	});
+});
+
+describe("section counts", () => {
+	test("Law: 5 books", () => {
+		expect(getBooksBySection("Law")).toHaveLength(5);
+	});
+
+	test("History: 13 books (12 OT + Acts)", () => {
+		expect(getBooksBySection("History")).toHaveLength(13);
+	});
+
+	test("Wisdom: 5 books", () => {
+		expect(getBooksBySection("Wisdom")).toHaveLength(5);
+	});
+
+	test("Major Prophets: 5 books", () => {
+		expect(getBooksBySection("Major Prophets")).toHaveLength(5);
+	});
+
+	test("Minor Prophets: 12 books", () => {
+		expect(getBooksBySection("Minor Prophets")).toHaveLength(12);
+	});
+
+	test("Gospels: 4 books", () => {
+		expect(getBooksBySection("Gospels")).toHaveLength(4);
+	});
+
+	test("Pauline Epistles: 13 books", () => {
+		expect(getBooksBySection("Pauline Epistles")).toHaveLength(13);
+	});
+
+	test("General Epistles: 8 books", () => {
+		expect(getBooksBySection("General Epistles")).toHaveLength(8);
+	});
+
+	test("Apocalyptic: 1 book (Revelation)", () => {
+		const books = getBooksBySection("Apocalyptic");
+		expect(books).toHaveLength(1);
+		expect(books[0].id).toBe("REV");
+	});
+
+	test("all sections sum to 66", () => {
+		const total =
+			getBooksBySection("Law").length +
+			getBooksBySection("History").length +
+			getBooksBySection("Wisdom").length +
+			getBooksBySection("Major Prophets").length +
+			getBooksBySection("Minor Prophets").length +
+			getBooksBySection("Gospels").length +
+			getBooksBySection("Pauline Epistles").length +
+			getBooksBySection("General Epistles").length +
+			getBooksBySection("Apocalyptic").length;
+		expect(total).toBe(66);
+	});
+});
+
+describe("getBookById", () => {
+	test("returns Genesis for GEN", () => {
+		const book = getBookById("GEN");
+		expect(book).toBeDefined();
+		expect(book!.name).toBe("Genesis");
+	});
+
+	test("returns Revelation for REV", () => {
+		const book = getBookById("REV");
+		expect(book!.name).toBe("Revelation");
+	});
+
+	test("returns undefined for unknown ID", () => {
+		expect(getBookById("UNKNOWN")).toBeUndefined();
+	});
+});
+
+describe("getBookByNumber", () => {
+	test("1 → Genesis", () => {
+		expect(getBookByNumber(1)!.id).toBe("GEN");
+	});
+
+	test("66 → Revelation", () => {
+		expect(getBookByNumber(66)!.id).toBe("REV");
+	});
+
+	test("40 → Matthew (first NT book)", () => {
+		expect(getBookByNumber(40)!.id).toBe("MAT");
+	});
+
+	test("0 → undefined", () => {
+		expect(getBookByNumber(0)).toBeUndefined();
+	});
+
+	test("67 → undefined", () => {
+		expect(getBookByNumber(67)).toBeUndefined();
+	});
+});
+
+describe("getBooksByTestament", () => {
+	test("old returns 39 books", () => {
+		expect(getBooksByTestament("old")).toHaveLength(39);
+	});
+
+	test("new returns 27 books", () => {
+		expect(getBooksByTestament("new")).toHaveLength(27);
+	});
+
+	test("all OT books have testament = old", () => {
+		for (const book of getBooksByTestament("old")) {
+			expect(book.testament).toBe("old");
+		}
+	});
+
+	test("all NT books have testament = new", () => {
+		for (const book of getBooksByTestament("new")) {
+			expect(book.testament).toBe("new");
+		}
+	});
+});
+
+describe("isAdjacent", () => {
+	test("Genesis and Exodus are adjacent", () => {
+		expect(isAdjacent("GEN", "EXO")).toBe(true);
+	});
+
+	test("adjacency is symmetric", () => {
+		expect(isAdjacent("EXO", "GEN")).toBe(true);
+	});
+
+	test("Malachi and Matthew are adjacent across testament boundary", () => {
+		expect(isAdjacent("MAL", "MAT")).toBe(true); // 39, 40
+	});
+
+	test("Jude and Revelation are adjacent", () => {
+		expect(isAdjacent("JUD", "REV")).toBe(true); // 65, 66
+	});
+
+	test("same book is not adjacent to itself", () => {
+		expect(isAdjacent("GEN", "GEN")).toBe(false);
+	});
+
+	test("books two apart are not adjacent", () => {
+		expect(isAdjacent("GEN", "LEV")).toBe(false); // 1, 3
+	});
+
+	test("returns false for invalid IDs", () => {
+		expect(isAdjacent("FAKE", "GEN")).toBe(false);
+	});
+});
+
+describe("bookNumberToId / bookIdToNumber lookup tables", () => {
+	test("bookNumberToId[1] is GEN", () => {
+		expect(bookNumberToId[1]).toBe("GEN");
+	});
+
+	test("bookNumberToId[66] is REV", () => {
+		expect(bookNumberToId[66]).toBe("REV");
+	});
+
+	test("bookIdToNumber['GEN'] is 1", () => {
+		expect(bookIdToNumber["GEN"]).toBe(1);
+	});
+
+	test("bookIdToNumber['REV'] is 66", () => {
+		expect(bookIdToNumber["REV"]).toBe(66);
+	});
+
+	test("round-trip: number → ID → number", () => {
+		for (let i = 1; i <= 66; i++) {
+			const id = bookNumberToId[i];
+			expect(bookIdToNumber[id]).toBe(i);
+		}
+	});
+
+	test("round-trip: ID → number → ID", () => {
+		for (const book of bibleBooks) {
+			const num = bookIdToNumber[book.id];
+			expect(bookNumberToId[num]).toBe(book.id);
+		}
+	});
+});
diff --git a/tests/game.test.ts b/tests/game.test.ts
new file mode 100644
index 0000000..24f3f15
--- /dev/null
+++ b/tests/game.test.ts
@@ -0,0 +1,271 @@
+import { describe, test, expect } from "bun:test";
+import {
+	evaluateGuess,
+	getBookById,
+	getFirstLetter,
+	getGrade,
+	getNextGradeMessage,
+	isAdjacent,
+	toOrdinal,
+} from "$lib/utils/game";
+
+describe("getBookById", () => {
+	test("returns correct book for a valid ID", () => {
+		const book = getBookById("GEN");
+		expect(book).toBeDefined();
+		expect(book!.name).toBe("Genesis");
+		expect(book!.order).toBe(1);
+	});
+
+	test("returns the last book by ID", () => {
+		const book = getBookById("REV");
+		expect(book).toBeDefined();
+		expect(book!.name).toBe("Revelation");
+		expect(book!.order).toBe(66);
+	});
+
+	test("returns undefined for an invalid ID", () => {
+		expect(getBookById("INVALID")).toBeUndefined();
+	});
+
+	test("returns undefined for an empty string", () => {
+		expect(getBookById("")).toBeUndefined();
+	});
+
+	test("is case-sensitive", () => {
+		expect(getBookById("gen")).toBeUndefined();
+	});
+});
+
+describe("isAdjacent", () => {
+	test("consecutive books are adjacent", () => {
+		expect(isAdjacent("GEN", "EXO")).toBe(true); // 1, 2
+	});
+
+	test("adjacency is symmetric", () => {
+		expect(isAdjacent("EXO", "GEN")).toBe(true);
+	});
+
+	test("books two apart are not adjacent", () => {
+		expect(isAdjacent("GEN", "LEV")).toBe(false); // 1, 3
+	});
+
+	test("the same book is not adjacent to itself", () => {
+		expect(isAdjacent("GEN", "GEN")).toBe(false); // diff = 0
+	});
+
+	test("works across testament boundary (Malachi / Matthew)", () => {
+		expect(isAdjacent("MAL", "MAT")).toBe(true); // 39, 40
+	});
+
+	test("far-apart books are not adjacent", () => {
+		expect(isAdjacent("GEN", "REV")).toBe(false);
+	});
+
+	test("returns false for unknown IDs", () => {
+		expect(isAdjacent("FAKE", "GEN")).toBe(false);
+		expect(isAdjacent("GEN", "FAKE")).toBe(false);
+	});
+});
+
+describe("getFirstLetter", () => {
+	test("returns first letter of a normal book name", () => {
+		expect(getFirstLetter("Genesis")).toBe("G");
+		expect(getFirstLetter("Revelation")).toBe("R");
+	});
+
+	test("skips leading digits and returns first letter", () => {
+		expect(getFirstLetter("1 Samuel")).toBe("S");
+		expect(getFirstLetter("2 Kings")).toBe("K");
+		expect(getFirstLetter("1 Corinthians")).toBe("C");
+		expect(getFirstLetter("3 John")).toBe("J");
+	});
+
+	test("returns first letter of multi-word names", () => {
+		expect(getFirstLetter("Song of Solomon")).toBe("S");
+	});
+});
+
+describe("evaluateGuess", () => {
+	test("returns null for an invalid guess ID", () => {
+		expect(evaluateGuess("INVALID", "GEN")).toBeNull();
+	});
+
+	test("returns null for an invalid correct ID", () => {
+		expect(evaluateGuess("GEN", "INVALID")).toBeNull();
+	});
+
+	test("exact book match: testamentMatch and sectionMatch are true, adjacent is false", () => {
+		const result = evaluateGuess("GEN", "GEN");
+		expect(result).not.toBeNull();
+		expect(result!.book.id).toBe("GEN");
+		expect(result!.testamentMatch).toBe(true);
+		expect(result!.sectionMatch).toBe(true);
+		expect(result!.adjacent).toBe(false);
+	});
+
+	test("same section implies same testament", () => {
+		// Genesis and Exodus are both OT Law
+		const result = evaluateGuess("GEN", "EXO");
+		expect(result!.testamentMatch).toBe(true);
+		expect(result!.sectionMatch).toBe(true);
+		expect(result!.adjacent).toBe(true);
+	});
+
+	test("same testament, different section", () => {
+		// Genesis (Law) vs Joshua (History) — both OT
+		const result = evaluateGuess("GEN", "JOS");
+		expect(result!.testamentMatch).toBe(true);
+		expect(result!.sectionMatch).toBe(false);
+		expect(result!.adjacent).toBe(false);
+	});
+
+	test("different testament, no match", () => {
+		// Genesis (OT) vs Matthew (NT)
+		const result = evaluateGuess("GEN", "MAT");
+		expect(result!.testamentMatch).toBe(false);
+		expect(result!.sectionMatch).toBe(false);
+		expect(result!.adjacent).toBe(false);
+	});
+
+	test("adjacent books across testament boundary", () => {
+		// Malachi (OT, 39) and Matthew (NT, 40)
+		const result = evaluateGuess("MAL", "MAT");
+		expect(result!.adjacent).toBe(true);
+		expect(result!.testamentMatch).toBe(false);
+		expect(result!.sectionMatch).toBe(false);
+	});
+
+	test("adjacent books within same testament and section", () => {
+		// Hosea (28) and Joel (29), both Minor Prophets
+		const result = evaluateGuess("HOS", "JOL");
+		expect(result!.adjacent).toBe(true);
+		expect(result!.testamentMatch).toBe(true);
+		expect(result!.sectionMatch).toBe(true);
+	});
+
+	test("firstLetterMatch: same first letter", () => {
+		// Genesis and Galatians both start with G
+		const result = evaluateGuess("GEN", "GAL");
+		expect(result!.firstLetterMatch).toBe(true);
+	});
+
+	test("firstLetterMatch: different first letter", () => {
+		// Genesis (G) vs Matthew (M)
+		const result = evaluateGuess("GEN", "MAT");
+		expect(result!.firstLetterMatch).toBe(false);
+	});
+
+	test("firstLetterMatch is case-insensitive", () => {
+		// Both start with J but from different contexts — Jeremiah vs Joel
+		const result = evaluateGuess("JER", "JOL");
+		expect(result!.firstLetterMatch).toBe(true);
+	});
+
+	test("special case: two Epistle '1' books always firstLetterMatch", () => {
+		// 1 Corinthians (Pauline) vs 1 John (General) — both Epistles starting with "1"
+		const result = evaluateGuess("1CO", "1JN");
+		expect(result!.firstLetterMatch).toBe(true);
+	});
+
+	test("special case: Epistle '1' book vs non-Epistle '1' book — no special treatment", () => {
+		// 1 Corinthians (Pauline Epistles) vs 1 Samuel (History)
+		// Correct is NOT Epistles, so special case doesn't apply
+		const result = evaluateGuess("1CO", "1SA");
+		// getFirstLetter("1 Corinthians") = "C", getFirstLetter("1 Samuel") = "S" → false
+		expect(result!.firstLetterMatch).toBe(false);
+	});
+
+	test("special case only triggers when BOTH are Epistle '1' books", () => {
+		// 2 Corinthians (Pauline, starts with "2") vs 1 John (General, starts with "1")
+		// guessIsEpistlesWithNumber requires name[0] === "1", so 2CO fails
+		const result = evaluateGuess("2CO", "1JN");
+		// getFirstLetter("2 Corinthians") = "C", getFirstLetter("1 John") = "J" → false
+		expect(result!.firstLetterMatch).toBe(false);
+	});
+});
+
+describe("getGrade", () => {
+	test("1 guess → S+", () => expect(getGrade(1)).toBe("S+"));
+	test("2 guesses → A+", () => expect(getGrade(2)).toBe("A+"));
+	test("3 guesses → A", () => expect(getGrade(3)).toBe("A"));
+	test("4 guesses → B+", () => expect(getGrade(4)).toBe("B+"));
+	test("6 guesses → B+", () => expect(getGrade(6)).toBe("B+"));
+	test("7 guesses → B", () => expect(getGrade(7)).toBe("B"));
+	test("10 guesses → B", () => expect(getGrade(10)).toBe("B"));
+	test("11 guesses → C+", () => expect(getGrade(11)).toBe("C+"));
+	test("15 guesses → C+", () => expect(getGrade(15)).toBe("C+"));
+	test("16 guesses → C", () => expect(getGrade(16)).toBe("C"));
+	test("100 guesses → C", () => expect(getGrade(100)).toBe("C"));
+});
+
+describe("getNextGradeMessage", () => {
+	test("returns empty string at top grade", () => {
+		expect(getNextGradeMessage(1)).toBe("");
+	});
+
+	test("grade A+ shows 1 guess threshold", () => {
+		expect(getNextGradeMessage(2)).toBe("Next grade: 1 guess or less");
+	});
+
+	test("grade A shows 2 guess threshold", () => {
+		expect(getNextGradeMessage(3)).toBe("Next grade: 2 guesses or less");
+	});
+
+	test("grade B+ shows 3 guess threshold", () => {
+		expect(getNextGradeMessage(4)).toBe("Next grade: 3 guesses or less");
+		expect(getNextGradeMessage(6)).toBe("Next grade: 3 guesses or less");
+	});
+
+	test("grade B shows 6 guess threshold", () => {
+		expect(getNextGradeMessage(7)).toBe("Next grade: 6 guesses or less");
+		expect(getNextGradeMessage(10)).toBe("Next grade: 6 guesses or less");
+	});
+
+	test("grade C+ shows 10 guess threshold", () => {
+		expect(getNextGradeMessage(11)).toBe("Next grade: 10 guesses or less");
+		expect(getNextGradeMessage(15)).toBe("Next grade: 10 guesses or less");
+	});
+
+	test("grade C shows 15 guess threshold", () => {
+		expect(getNextGradeMessage(16)).toBe("Next grade: 15 guesses or less");
+		expect(getNextGradeMessage(50)).toBe("Next grade: 15 guesses or less");
+	});
+});
+
+describe("toOrdinal", () => {
+	test("1st, 2nd, 3rd", () => {
+		expect(toOrdinal(1)).toBe("1st");
+		expect(toOrdinal(2)).toBe("2nd");
+		expect(toOrdinal(3)).toBe("3rd");
+	});
+
+	test("4-10 use th", () => {
+		expect(toOrdinal(4)).toBe("4th");
+		expect(toOrdinal(10)).toBe("10th");
+	});
+
+	test("11, 12, 13 use th (not st/nd/rd)", () => {
+		expect(toOrdinal(11)).toBe("11th");
+		expect(toOrdinal(12)).toBe("12th");
+		expect(toOrdinal(13)).toBe("13th");
+	});
+
+	test("21, 22, 23 use st/nd/rd", () => {
+		expect(toOrdinal(21)).toBe("21st");
+		expect(toOrdinal(22)).toBe("22nd");
+		expect(toOrdinal(23)).toBe("23rd");
+	});
+
+	test("101, 102, 103 use st/nd/rd", () => {
+		expect(toOrdinal(101)).toBe("101st");
+		expect(toOrdinal(102)).toBe("102nd");
+		expect(toOrdinal(103)).toBe("103rd");
+	});
+
+	test("111, 112, 113 use th", () => {
+		expect(toOrdinal(111)).toBe("111th");
+		expect(toOrdinal(112)).toBe("112th");
+		expect(toOrdinal(113)).toBe("113th");
+	});
+});
diff --git a/tests/share.test.ts b/tests/share.test.ts
new file mode 100644
index 0000000..29bc50c
--- /dev/null
+++ b/tests/share.test.ts
@@ -0,0 +1,339 @@
+import { describe, test, expect } from "bun:test";
+import { generateShareText, getVerseSnippet } from "$lib/utils/share";
+import { getBookById } from "$lib/utils/game";
+import type { Guess } from "$lib/utils/game";
+
+// Helpers to build Guess objects without calling evaluateGuess
+function makeGuess(bookId: string, overrides: Partial<Omit<Guess, "book">> = {}): Guess {
+	const book = getBookById(bookId)!;
+	return {
+		book,
+		testamentMatch: false,
+		sectionMatch: false,
+		adjacent: false,
+		firstLetterMatch: false,
+		...overrides,
+	};
+}
+
+const CORRECT_BOOK_ID = "GEN";
+
+const exactGuess = makeGuess("GEN", {
+	testamentMatch: true,
+	sectionMatch: true,
+});
+
+const adjacentGuess = makeGuess("EXO", {
+	testamentMatch: true,
+	sectionMatch: true,
+	adjacent: true,
+});
+
+const sectionGuess = makeGuess("LEV", {
+	testamentMatch: true,
+	sectionMatch: true,
+});
+
+const testamentGuess = makeGuess("JOS", {
+	testamentMatch: true,
+	sectionMatch: false,
+});
+
+const noMatchGuess = makeGuess("MAT", {
+	testamentMatch: false,
+	sectionMatch: false,
+});
+
+describe("generateShareText — emoji mapping", () => {
+	test("exact match → ✅", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "In the beginning...",
+		});
+		expect(text).toContain("✅");
+	});
+
+	test("adjacent book → ‼️", () => {
+		const text = generateShareText({
+			guesses: [adjacentGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "In the beginning...",
+		});
+		expect(text).toContain("‼️");
+	});
+
+	test("section match → 🟩", () => {
+		// LEV matches section (Law) but is not adjacent to GEN (order 1 vs 3)
+		const text = generateShareText({
+			guesses: [sectionGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "In the beginning...",
+		});
+		expect(text).toContain("🟩");
+	});
+
+	test("testament match only → 🟧", () => {
+		const text = generateShareText({
+			guesses: [testamentGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "In the beginning...",
+		});
+		expect(text).toContain("🟧");
+	});
+
+	test("no match → 🟥", () => {
+		const text = generateShareText({
+			guesses: [noMatchGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "In the beginning...",
+		});
+		expect(text).toContain("🟥");
+	});
+});
+
+describe("generateShareText — guess count wording", () => {
+	test("1 guess uses singular 'guess'", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("1 guess,");
+	});
+
+	test("multiple guesses uses plural 'guesses'", () => {
+		const text = generateShareText({
+			guesses: [noMatchGuess, testamentGuess, exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("3 guesses,");
+	});
+});
+
+describe("generateShareText — streak display", () => {
+	test("streak > 1 is shown with fire emoji", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			streak: 5,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("5 days 🔥");
+	});
+
+	test("streak of 1 is not shown", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			streak: 1,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).not.toContain("🔥");
+	});
+
+	test("undefined streak is not shown", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).not.toContain("🔥");
+	});
+});
+
+describe("generateShareText — chapter star", () => {
+	test("1 guess + chapterCorrect → ⭐ appended to emoji line", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: true,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("✅ ⭐");
+	});
+
+	test("multiple guesses + chapterCorrect → no star (only awarded for hole-in-one)", () => {
+		const text = generateShareText({
+			guesses: [noMatchGuess, exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: true,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).not.toContain("⭐");
+	});
+
+	test("1 guess + chapterCorrect false → no star", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).not.toContain("⭐");
+	});
+});
+
+describe("generateShareText — login book emoji", () => {
+	test("logged in uses 📜", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: true,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("📜");
+		expect(text).not.toContain("📖");
+	});
+
+	test("not logged in uses 📖", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("📖");
+		expect(text).not.toContain("📜");
+	});
+});
+
+describe("generateShareText — date formatting", () => {
+	test("date is formatted as 'Mon DD, YYYY'", () => {
+		const text = generateShareText({
+			guesses: [exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		expect(text).toContain("Jan 15, 2025");
+	});
+});
+
+describe("generateShareText — guess order", () => {
+	test("guesses are reversed in the emoji line (first guess last)", () => {
+		// noMatchGuess first, then exactGuess — reversed output: ✅🟥
+		const text = generateShareText({
+			guesses: [noMatchGuess, exactGuess],
+			correctBookId: CORRECT_BOOK_ID,
+			dailyVerseDate: "2025-01-15",
+			chapterCorrect: false,
+			isLoggedIn: false,
+			origin: "https://bibdle.com",
+			verseText: "...",
+		});
+		const lines = text.split("\n");
+		expect(lines[2]).toBe("✅🟥");
+	});
+});
+
+describe("getVerseSnippet", () => {
+	test("wraps output in curly double quotes", () => {
+		const result = getVerseSnippet("Hello world");
+		expect(result.startsWith("\u201C")).toBe(true);
+		expect(result.endsWith("\u201D")).toBe(true);
+	});
+
+	test("short verse (fewer than 10 words) returns full text", () => {
+		const result = getVerseSnippet("For God so loved");
+		// No punctuation search happens, returns all words
+		expect(result).toContain("For God so loved");
+		expect(result).toContain("...");
+	});
+
+	test("verse with no punctuation in range returns first 25 words", () => {
+		const words = Array.from({ length: 30 }, (_, i) => `word${i + 1}`);
+		const verse = words.join(" ");
+		const result = getVerseSnippet(verse);
+		// Should contain up to 25 words
+		expect(result).toContain("word25");
+		expect(result).not.toContain("word26");
+	});
+
+	test("truncates at punctuation between words 10 and 25", () => {
+		// 12 words before comma, rest after
+		const verse =
+			"one two three four five six seven eight nine ten eleven twelve, thirteen fourteen fifteen twenty";
+		const result = getVerseSnippet(verse);
+		// The comma is after word 12, which is between word 10 and 25
+		expect(result).toContain("twelve");
+		expect(result).not.toContain("thirteen");
+	});
+
+	test("punctuation before word 10 does not trigger truncation", () => {
+		// Comma is after word 5 — before the search window starts at word 10
+		const verse =
+			"one two three four five, six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen";
+		const result = getVerseSnippet(verse);
+		// The comma at word 5 is before start of search range, so we continue
+		// The snippet should contain word 10 at minimum
+		expect(result).toContain("ten");
+	});
+
+	test("does not include trailing whitespace before ellipsis", () => {
+		const verse =
+			"one two three four five six seven eight nine ten eleven twelve, rest of verse here";
+		const result = getVerseSnippet(verse);
+		// trimEnd is applied before adding ..., so no space before ...
+		expect(result).not.toMatch(/\s\.\.\./);
+	});
+});
diff --git a/tests/stats.test.ts b/tests/stats.test.ts
new file mode 100644
index 0000000..4d89ae1
--- /dev/null
+++ b/tests/stats.test.ts
@@ -0,0 +1,129 @@
+import { describe, test, expect } from "bun:test";
+import {
+	formatDate,
+	getGradeColor,
+	getPerformanceMessage,
+	getStreakMessage,
+} from "$lib/utils/stats";
+
+describe("getGradeColor", () => {
+	test("S++ → purple", () => {
+		expect(getGradeColor("S++")).toBe("text-purple-600 bg-purple-100");
+	});
+
+	test("S+ → yellow", () => {
+		expect(getGradeColor("S+")).toBe("text-yellow-600 bg-yellow-100");
+	});
+
+	test("A+ → green", () => {
+		expect(getGradeColor("A+")).toBe("text-green-600 bg-green-100");
+	});
+
+	test("A → light green", () => {
+		expect(getGradeColor("A")).toBe("text-green-500 bg-green-50");
+	});
+
+	test("B+ → blue", () => {
+		expect(getGradeColor("B+")).toBe("text-blue-600 bg-blue-100");
+	});
+
+	test("B → light blue", () => {
+		expect(getGradeColor("B")).toBe("text-blue-500 bg-blue-50");
+	});
+
+	test("C+ → orange", () => {
+		expect(getGradeColor("C+")).toBe("text-orange-600 bg-orange-100");
+	});
+
+	test("C → red", () => {
+		expect(getGradeColor("C")).toBe("text-red-600 bg-red-100");
+	});
+
+	test("unknown grade → gray fallback", () => {
+		expect(getGradeColor("X")).toBe("text-gray-600 bg-gray-100");
+		expect(getGradeColor("")).toBe("text-gray-600 bg-gray-100");
+	});
+});
+
+describe("formatDate", () => {
+	test("formats a mid-year date", () => {
+		expect(formatDate("2024-07-04")).toBe("Jul 4");
+	});
+
+	test("formats a January date", () => {
+		expect(formatDate("2024-01-15")).toBe("Jan 15");
+	});
+
+	test("formats the last day of the year", () => {
+		expect(formatDate("2023-12-31")).toBe("Dec 31");
+	});
+
+	test("formats a single-digit day without leading zero", () => {
+		expect(formatDate("2025-03-01")).toBe("Mar 1");
+	});
+
+	test("year in input does not appear in output", () => {
+		expect(formatDate("2024-06-20")).not.toContain("2024");
+	});
+});
+
+describe("getStreakMessage", () => {
+	test("0 → prompt to start", () => {
+		expect(getStreakMessage(0)).toBe("Start your streak today!");
+	});
+
+	test("1 → encouragement", () => {
+		expect(getStreakMessage(1)).toBe("Keep it going!");
+	});
+
+	test("2 → X days strong", () => {
+		expect(getStreakMessage(2)).toBe("2 days strong!");
+	});
+
+	test("6 → X days strong (upper bound of that range)", () => {
+		expect(getStreakMessage(6)).toBe("6 days strong!");
+	});
+
+	test("7 → week streak message", () => {
+		expect(getStreakMessage(7)).toBe("7 day streak - amazing!");
+	});
+
+	test("29 → upper bound of week-streak range", () => {
+		expect(getStreakMessage(29)).toBe("29 day streak - amazing!");
+	});
+
+	test("30 → unstoppable message", () => {
+		expect(getStreakMessage(30)).toBe("30 days - you're unstoppable!");
+	});
+
+	test("100 → unstoppable message", () => {
+		expect(getStreakMessage(100)).toBe("100 days - you're unstoppable!");
+	});
+});
+
+describe("getPerformanceMessage", () => {
+	test("≤ 2 guesses → exceptional", () => {
+		expect(getPerformanceMessage(1)).toBe("Exceptional performance!");
+		expect(getPerformanceMessage(2)).toBe("Exceptional performance!");
+	});
+
+	test("≤ 4 guesses → great", () => {
+		expect(getPerformanceMessage(2.1)).toBe("Great performance!");
+		expect(getPerformanceMessage(4)).toBe("Great performance!");
+	});
+
+	test("≤ 6 guesses → good", () => {
+		expect(getPerformanceMessage(4.1)).toBe("Good performance!");
+		expect(getPerformanceMessage(6)).toBe("Good performance!");
+	});
+
+	test("≤ 8 guesses → room for improvement", () => {
+		expect(getPerformanceMessage(6.1)).toBe("Room for improvement!");
+		expect(getPerformanceMessage(8)).toBe("Room for improvement!");
+	});
+
+	test("> 8 guesses → keep practicing", () => {
+		expect(getPerformanceMessage(8.1)).toBe("Keep practicing!");
+		expect(getPerformanceMessage(20)).toBe("Keep practicing!");
+	});
+});