oh-my-pi/packages/utils/test/mermaid/multiline.test.ts

import { describe, expect, it } from "bun:test";
import { renderMermaidAscii } from "../../src/vendor/mermaid-ascii/ascii/index";

describe("ASCII multi-line labels", () => {
	describe("flowchart nodes", () => {
		it("renders multi-line node labels", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[Line1<br>Line2]", { useAscii: false });
			expect(ascii).toContain("Line1");
			expect(ascii).toContain("Line2");
			// Lines should be on different rows
			const lines = ascii.split("\n");
			const line1Row = lines.findIndex(l => l.includes("Line1"));
			const line2Row = lines.findIndex(l => l.includes("Line2"));
			expect(line2Row).toBeGreaterThan(line1Row);
		});

		it("handles 3+ line labels", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[A<br>B<br>C]", { useAscii: false });
			expect(ascii).toContain("A");
			expect(ascii).toContain("B");
			expect(ascii).toContain("C");
			// Verify vertical ordering
			const lines = ascii.split("\n");
			const aRow = lines.findIndex(l => l.includes("A") && !l.includes("─") && !l.includes("-"));
			const bRow = lines.findIndex(l => l.includes("B"));
			const cRow = lines.findIndex(l => l.includes("C"));
			expect(bRow).toBeGreaterThan(aRow);
			expect(cRow).toBeGreaterThan(bRow);
		});

		it("renders in ASCII mode (not Unicode)", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[Line1<br>Line2]", { useAscii: true });
			expect(ascii).toContain("Line1");
			expect(ascii).toContain("Line2");
			// Should use ASCII box characters
			expect(ascii).toContain("+");
			expect(ascii).toContain("-");
		});
	});

	describe("flowchart edge labels", () => {
		it("renders multi-line edge labels", () => {
			const ascii = renderMermaidAscii("graph TD\n  A --> B\n  A -->|Line1<br>Line2| C", { useAscii: false });
			expect(ascii).toContain("Line1");
			expect(ascii).toContain("Line2");
		});
	});

	describe("flowchart subgraph labels", () => {
		it("renders multi-line subgraph labels", () => {
			const ascii = renderMermaidAscii(
				`graph TD
        subgraph sg [Group<br>Header]
          A[Node]
        end
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Group");
			expect(ascii).toContain("Header");
		});
	});

	describe("sequence diagram", () => {
		it("renders multi-line actor labels", () => {
			const ascii = renderMermaidAscii(
				`sequenceDiagram
        participant A as Actor<br>One
        A->>A: msg
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Actor");
			expect(ascii).toContain("One");
		});

		it("renders multi-line message labels", () => {
			const ascii = renderMermaidAscii(
				`sequenceDiagram
        participant A
        participant B
        A->>B: Line1<br>Line2
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Line1");
			expect(ascii).toContain("Line2");
		});

		it("preserves existing note multi-line support", () => {
			const ascii = renderMermaidAscii(
				`sequenceDiagram
        participant A
        A->>A: self
        Note over A: Note line 1<br>Note line 2
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Note line 1");
			expect(ascii).toContain("Note line 2");
		});
	});

	describe("class diagram", () => {
		it("renders multi-line class names", () => {
			const ascii = renderMermaidAscii(
				`classDiagram
        class MyClass["Long<br>Name"]
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Long");
			expect(ascii).toContain("Name");
		});

		it("renders multi-line relationship labels", () => {
			const ascii = renderMermaidAscii(
				`classDiagram
        A --> B : uses<br>implements
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("uses");
			expect(ascii).toContain("implements");
		});
	});

	describe("ER diagram", () => {
		it("renders multi-line entity names", () => {
			const ascii = renderMermaidAscii(
				`erDiagram
        "Entity<br>Name" {
          string id
        }
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("Entity");
			expect(ascii).toContain("Name");
		});

		it("renders multi-line relationship labels", () => {
			const ascii = renderMermaidAscii(
				`erDiagram
        A ||--o{ B : "has<br>many"
      `,
				{ useAscii: false },
			);
			expect(ascii).toContain("has");
			expect(ascii).toContain("many");
		});
	});

	describe("edge cases", () => {
		it("handles empty lines from consecutive <br>", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[Line1<br><br>Line3]", { useAscii: false });
			expect(ascii).toContain("Line1");
			expect(ascii).toContain("Line3");
		});

		it("handles single-line labels (no <br>)", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[SingleLine]", { useAscii: false });
			expect(ascii).toContain("SingleLine");
		});

		it("handles very long lines", () => {
			const long = "A".repeat(30);
			const ascii = renderMermaidAscii(`graph TD\n  A[${long}<br>Short]`, { useAscii: false });
			expect(ascii).toContain(long);
			expect(ascii).toContain("Short");
		});

		it("handles mixed short and long lines", () => {
			const ascii = renderMermaidAscii("graph TD\n  A[Short<br>VeryLongSecondLine<br>Med]", { useAscii: false });
			expect(ascii).toContain("Short");
			expect(ascii).toContain("VeryLongSecondLine");
			expect(ascii).toContain("Med");
		});
	});

	describe("multiline-utils functions", () => {
		it("splitLines splits on newlines", () => {
			// Test through the rendering pipeline
			const ascii = renderMermaidAscii("graph TD\n  A[One<br>Two<br>Three]", { useAscii: false });
			const lines = ascii.split("\n");
			// All three words should appear on separate lines
			expect(lines.some(l => l.includes("One"))).toBe(true);
			expect(lines.some(l => l.includes("Two"))).toBe(true);
			expect(lines.some(l => l.includes("Three"))).toBe(true);
		});

		it("maxLineWidth uses longest line for box sizing", () => {
			// Box should be wide enough for the longest line
			const ascii = renderMermaidAscii("graph TD\n  A[X<br>LongLine<br>Y]", { useAscii: false });
			// The box should contain LongLine without truncation
			expect(ascii).toContain("LongLine");
		});
	});
});