[UI] add line wrapping functionality

Tests/SwiftMathTests/MTMathUILabelLineWrappingTests.swift

@@ -0,0 +1,194 @@
+//
+//  MTMathUILabelLineWrappingTests.swift
+//  SwiftMathTests
+//
+//  Tests for line wrapping functionality in MTMathUILabel
+//
+
+import XCTest
+@testable import SwiftMath
+
+class MTMathUILabelLineWrappingTests: XCTestCase {
+
+    func testBasicIntrinsicContentSize() {
+        let label = MTMathUILabel()
+        label.latex = "\\(x + y\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+
+        // Debug: check if parsing worked
+        XCTAssertNotNil(label.mathList, "Math list should not be nil")
+        XCTAssertNil(label.error, "Should have no parsing error, got: \(String(describing: label.error))")
+        XCTAssertNotNil(label.font, "Font should not be nil")
+
+        let size = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+    }
+
+    func testTextModeIntrinsicContentSize() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Hello World}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        let size = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+    }
+
+    func testLongTextIntrinsicContentSize() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Rappelons la conversion : 1 km équivaut à 1000 m.}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        let size = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+    }
+
+    func testSizeThatFitsWithoutConstraint() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Hello World}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+
+        let size = label.sizeThatFits(CGSize.zero)
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+    }
+
+    func testSizeThatFitsWithWidthConstraint() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Rappelons la conversion : 1 km équivaut à 1000 m.}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        // Get unconstrained size first
+        let unconstrainedSize = label.sizeThatFits(CGSize.zero)
+        XCTAssertGreaterThan(unconstrainedSize.width, 0, "Unconstrained width should be > 0")
+
+        // Test with width constraint (use 300 since longest word might be ~237pt)
+        let constrainedSize = label.sizeThatFits(CGSize(width: 300, height: CGFloat.greatestFiniteMagnitude))
+
+        XCTAssertGreaterThan(constrainedSize.width, 0, "Constrained width should be greater than 0, got \(constrainedSize.width)")
+        XCTAssertLessThan(constrainedSize.width, unconstrainedSize.width, "Constrained width (\(constrainedSize.width)) should be less than unconstrained (\(unconstrainedSize.width))")
+        XCTAssertGreaterThan(constrainedSize.height, 0, "Constrained height should be greater than 0, got \(constrainedSize.height)")
+
+        // When constrained, height should increase when text wraps
+        XCTAssertGreaterThan(constrainedSize.height, unconstrainedSize.height,
+                            "Constrained height (\(constrainedSize.height)) should be > unconstrained (\(unconstrainedSize.height)) when text wraps")
+    }
+
+    func testPreferredMaxLayoutWidth() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Rappelons la conversion : 1 km équivaut à 1000 m.}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        // Get unconstrained size
+        let unconstrainedSize = label.intrinsicContentSize
+
+        // Now set preferred max width (use 300 since longest word might be ~237pt)
+        label.preferredMaxLayoutWidth = 300
+        let constrainedSize = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(constrainedSize.width, 0, "Width should be greater than 0, got \(constrainedSize.width)")
+        XCTAssertLessThan(constrainedSize.width, unconstrainedSize.width, "Constrained width (\(constrainedSize.width)) should be < unconstrained (\(unconstrainedSize.width))")
+        XCTAssertGreaterThan(constrainedSize.height, unconstrainedSize.height, "Constrained height (\(constrainedSize.height)) should be > unconstrained (\(unconstrainedSize.height)) due to wrapping")
+    }
+
+    func testWordBoundaryBreaking() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Word1 Word2 Word3 Word4 Word5}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+        label.preferredMaxLayoutWidth = 150
+
+        let size = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+
+        // Verify it actually uses the layout
+        label.frame = CGRect(origin: .zero, size: size)
+        #if os(macOS)
+        label.layout()
+        #else
+        label.layoutSubviews()
+        #endif
+
+        XCTAssertNotNil(label.displayList, "Display list should be created")
+    }
+
+    func testEmptyLatex() {
+        let label = MTMathUILabel()
+        label.latex = ""
+        label.font = MTFontManager.fontManager.defaultFont
+
+        let size = label.intrinsicContentSize
+
+        // Empty latex should still return a valid size (might be zero or minimal)
+        XCTAssertGreaterThanOrEqual(size.width, 0, "Width should be >= 0 for empty latex, got \(size.width)")
+        XCTAssertGreaterThanOrEqual(size.height, 0, "Height should be >= 0 for empty latex, got \(size.height)")
+    }
+
+    func testMathAndTextMixed() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Result: } x^2 + y^2 = z^2\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        let size = label.intrinsicContentSize
+
+        XCTAssertGreaterThan(size.width, 0, "Width should be greater than 0, got \(size.width)")
+        XCTAssertGreaterThan(size.height, 0, "Height should be greater than 0, got \(size.height)")
+    }
+
+    func testDebugSizeThatFitsWithConstraint() {
+        let label = MTMathUILabel()
+        label.latex = "\\(\\text{Word1 Word2 Word3 Word4 Word5}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        let unconstr = label.sizeThatFits(CGSize.zero)
+        let constr = label.sizeThatFits(CGSize(width: 150, height: 999))
+
+        XCTAssertLessThan(constr.width, unconstr.width, "Constrained (\(constr.width)) should be < unconstrained (\(unconstr.width))")
+        XCTAssertGreaterThan(constr.height, unconstr.height, "Constrained height (\(constr.height)) should be > unconstrained (\(unconstr.height))")
+    }
+
+    func testAccentedCharactersWithLineWrapping() {
+        let label = MTMathUILabel()
+        // French text with accented characters: è, é, à
+        label.latex = "\\(\\text{Rappelons la relation entre kilomètres et mètres.}\\)"
+        label.font = MTFontManager.fontManager.defaultFont
+        label.labelMode = .text
+
+        // Get unconstrained size
+        let unconstrainedSize = label.intrinsicContentSize
+
+        // Set a width constraint that should cause wrapping
+        label.preferredMaxLayoutWidth = 250
+        let constrainedSize = label.intrinsicContentSize
+
+        // Verify wrapping occurred
+        XCTAssertGreaterThan(constrainedSize.width, 0, "Width should be > 0")
+        XCTAssertLessThan(constrainedSize.width, unconstrainedSize.width, "Constrained width should be < unconstrained")
+        XCTAssertGreaterThan(constrainedSize.height, unconstrainedSize.height, "Height should increase when wrapped")
+
+        // Verify the label can render without errors
+        label.frame = CGRect(origin: .zero, size: constrainedSize)
+        #if os(macOS)
+        label.layout()
+        #else
+        label.layoutSubviews()
+        #endif
+
+        XCTAssertNotNil(label.displayList, "Display list should be created")
+        XCTAssertNil(label.error, "Should have no rendering error")
+    }
+}