docs: mention direnv in README bootstrap section

Provide a reproducible dev shell with JDK 17 and Maven 3.9.x.
JDK 17 (LTS) is used since JDK 16 (project target) is non-LTS
and unavailable in nixpkgs; it is fully backward-compatible with
--source 16 --target 16. Maven is overridden via overlay to use
the same JDK.

.envrc

@@ -0,0 +1 @@
+use flake

README.md

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+# new-shapes
+
+A shape editor desktop application built with Java Swing. Supports rectangles, circles, triangles, text, shape collections, resize handles, and export to HTML/SVG.
+
+## Prerequisites
+
+- JDK >= 16 (project targets Java 16)
+- A graphical display (X11/Wayland) since this is a Swing GUI application
+
+## Bootstrap
+
+### With Nix (recommended)
+
+If you have [direnv](https://direnv.net/) installed, the environment activates automatically:
+
+```sh
+direnv allow   # one-time, then auto-activates on cd
+```
+
+Otherwise, enter the dev shell manually:
+
+```sh
+nix develop
+```
+
+Both provide JDK 17 and Maven 3.9.x preconfigured. No other setup needed.
+
+### Without Nix
+
+Install JDK 16+ and use the bundled Maven wrapper — no separate Maven installation required:
+
+```sh
+./mvnw --version   # downloads Maven 3.9.12 on first run
+```
+
+## Run the application
+
+```sh
+./mvnw compile exec:java -Dexec.mainClass="ovh.gasser.newshapes.App"
+```
+
+## Run tests
+
+```sh
+./mvnw test
+```
+
+To run the full verification pipeline (compile, test, JaCoCo coverage check with 50% minimum line coverage):
+
+```sh
+./mvnw verify
+```
+
+Coverage reports are generated in `target/site/jacoco/`.

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1774386573,
+        "narHash": "sha256-4hAV26quOxdC6iyG7kYaZcM3VOskcPUrdCQd/nx8obc=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "46db2e09e1d3f113a13c0d7b81e2f221c63b8ce9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,48 @@
+{
+  description = "new-shapes - Java Swing shape editor";
+
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+
+  outputs = { self, nixpkgs }:
+    let
+      # JDK 16 (project target) is non-LTS and unavailable in nixpkgs.
+      # JDK 17 (LTS) is fully backward-compatible with --source 16 --target 16.
+      javaVersion = 17;
+
+      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+
+      forEachSystem = f:
+        nixpkgs.lib.genAttrs supportedSystems (system: f {
+          pkgs = import nixpkgs {
+            inherit system;
+            overlays = [ self.overlays.default ];
+          };
+        });
+    in
+    {
+      overlays.default = final: prev:
+        let
+          jdk = prev."jdk${toString javaVersion}";
+        in
+        {
+          inherit jdk;
+          # Override Maven to use the same JDK version
+          maven = prev.maven.override { jdk_headless = jdk; };
+        };
+
+      devShells = forEachSystem ({ pkgs }: {
+        default = pkgs.mkShell {
+          packages = with pkgs; [
+            jdk
+            maven
+          ];
+
+          shellHook = ''
+            echo "new-shapes dev shell"
+            echo "  Java: $(java -version 2>&1 | head -1)"
+            echo "  Maven: $(mvn -version 2>&1 | head -1)"
+          '';
+        };
+      });
+    };
+}

src/test/java/ovh/gasser/newshapes/shapes/ResizeHandleTest.java

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+package ovh.gasser.newshapes.shapes;
+
+import org.junit.jupiter.api.Test;
+import java.awt.Cursor;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ResizeHandleTest {
+
+    @Test
+    void testEightHandlesExist() {
+        assertEquals(8, ResizeHandle.values().length,
+                "ResizeHandle enum should define exactly 8 handles");
+    }
+
+    @Test
+    void testAllHandleNamesExist() {
+        assertNotNull(ResizeHandle.valueOf("NW"), "Handle NW should exist");
+        assertNotNull(ResizeHandle.valueOf("N"),  "Handle N should exist");
+        assertNotNull(ResizeHandle.valueOf("NE"), "Handle NE should exist");
+        assertNotNull(ResizeHandle.valueOf("E"),  "Handle E should exist");
+        assertNotNull(ResizeHandle.valueOf("SE"), "Handle SE should exist");
+        assertNotNull(ResizeHandle.valueOf("S"),  "Handle S should exist");
+        assertNotNull(ResizeHandle.valueOf("SW"), "Handle SW should exist");
+        assertNotNull(ResizeHandle.valueOf("W"),  "Handle W should exist");
+    }
+
+    @Test
+    void testNwMapsToCorrectCursorType() {
+        assertEquals(Cursor.NW_RESIZE_CURSOR, ResizeHandle.NW.getCursorType(),
+                "NW handle should map to Cursor.NW_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testNMapsToCorrectCursorType() {
+        assertEquals(Cursor.N_RESIZE_CURSOR, ResizeHandle.N.getCursorType(),
+                "N handle should map to Cursor.N_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testNeMapsToCorrectCursorType() {
+        assertEquals(Cursor.NE_RESIZE_CURSOR, ResizeHandle.NE.getCursorType(),
+                "NE handle should map to Cursor.NE_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testEMapsToCorrectCursorType() {
+        assertEquals(Cursor.E_RESIZE_CURSOR, ResizeHandle.E.getCursorType(),
+                "E handle should map to Cursor.E_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testSeMapsToCorrectCursorType() {
+        assertEquals(Cursor.SE_RESIZE_CURSOR, ResizeHandle.SE.getCursorType(),
+                "SE handle should map to Cursor.SE_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testSMapsToCorrectCursorType() {
+        assertEquals(Cursor.S_RESIZE_CURSOR, ResizeHandle.S.getCursorType(),
+                "S handle should map to Cursor.S_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testSwMapsToCorrectCursorType() {
+        assertEquals(Cursor.SW_RESIZE_CURSOR, ResizeHandle.SW.getCursorType(),
+                "SW handle should map to Cursor.SW_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testWMapsToCorrectCursorType() {
+        assertEquals(Cursor.W_RESIZE_CURSOR, ResizeHandle.W.getCursorType(),
+                "W handle should map to Cursor.W_RESIZE_CURSOR");
+    }
+
+    @Test
+    void testValueOfReturnsCorrectConstant() {
+        assertSame(ResizeHandle.NW, ResizeHandle.valueOf("NW"), "valueOf(\"NW\") should return ResizeHandle.NW");
+        assertSame(ResizeHandle.N,  ResizeHandle.valueOf("N"),  "valueOf(\"N\") should return ResizeHandle.N");
+        assertSame(ResizeHandle.NE, ResizeHandle.valueOf("NE"), "valueOf(\"NE\") should return ResizeHandle.NE");
+        assertSame(ResizeHandle.E,  ResizeHandle.valueOf("E"),  "valueOf(\"E\") should return ResizeHandle.E");
+        assertSame(ResizeHandle.SE, ResizeHandle.valueOf("SE"), "valueOf(\"SE\") should return ResizeHandle.SE");
+        assertSame(ResizeHandle.S,  ResizeHandle.valueOf("S"),  "valueOf(\"S\") should return ResizeHandle.S");
+        assertSame(ResizeHandle.SW, ResizeHandle.valueOf("SW"), "valueOf(\"SW\") should return ResizeHandle.SW");
+        assertSame(ResizeHandle.W,  ResizeHandle.valueOf("W"),  "valueOf(\"W\") should return ResizeHandle.W");
+    }
+
+    @Test
+    void testValueOfWithInvalidNameThrowsIllegalArgumentException() {
+        assertThrows(IllegalArgumentException.class,
+                () -> ResizeHandle.valueOf("INVALID"),
+                "valueOf() with an unknown name should throw IllegalArgumentException");
+    }
+}

src/test/java/ovh/gasser/newshapes/ui/visitors/SVGDraftmanTest.java

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+package ovh.gasser.newshapes.ui.visitors;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import ovh.gasser.newshapes.attributes.ColorAttributes;
+import ovh.gasser.newshapes.shapes.*;
+
+import java.awt.*;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class SVGDraftmanTest {
+
+    private StringWriter buffer;
+    private PrintWriter writer;
+    private SVGDraftman draftman;
+
+    @BeforeEach
+    void setUp() {
+        buffer = new StringWriter();
+        writer = new PrintWriter(buffer);
+        draftman = new SVGDraftman(writer);
+    }
+
+    private String output() {
+        writer.flush();
+        return buffer.toString();
+    }
+
+    // ── visitRectangle ──────────────────────────────────────────────
+
+    @Nested
+    class VisitRectangleTests {
+
+        @Test
+        void testRectangleElementWithCorrectDimensions() {
+            SRectangle rect = SRectangle.create(10, 20, 100, 50);
+            draftman.visitRectangle(rect);
+
+            String svg = output();
+            assertTrue(svg.contains("<rect"), "Should produce a <rect> element");
+            assertTrue(svg.contains("width=\"100\""), "Should have correct width");
+            assertTrue(svg.contains("height=\"50\""), "Should have correct height");
+            assertTrue(svg.contains("x=\"10\""), "Should have correct x");
+            assertTrue(svg.contains("y=\"20\""), "Should have correct y");
+        }
+
+        @Test
+        void testRectangleFilledOnly() {
+            SRectangle rect = SRectangle.create(0, 0, 30, 30);
+            rect.addAttributes(new ColorAttributes(true, false, Color.RED, Color.BLACK));
+            draftman.visitRectangle(rect);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#ff0000\""), "Should contain fill color");
+            assertFalse(svg.contains("stroke="), "Should not contain stroke when stroked=false");
+        }
+
+        @Test
+        void testRectangleStrokedOnly() {
+            SRectangle rect = SRectangle.create(0, 0, 30, 30);
+            rect.addAttributes(new ColorAttributes(false, true, Color.RED, Color.BLUE));
+            draftman.visitRectangle(rect);
+
+            String svg = output();
+            assertTrue(svg.contains("stroke=\"#0000ff\""), "Should contain stroke color");
+            assertTrue(svg.contains("stroke-width=\"1\""), "Should contain stroke-width");
+            assertTrue(svg.contains("fill=\"none\""), "Should have fill=none when not filled");
+        }
+
+        @Test
+        void testRectangleFilledAndStroked() {
+            SRectangle rect = SRectangle.create(0, 0, 30, 30);
+            rect.addAttributes(new ColorAttributes(true, true, Color.RED, Color.BLUE));
+            draftman.visitRectangle(rect);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#ff0000\""), "Should contain fill color");
+            assertTrue(svg.contains("stroke=\"#0000ff\""), "Should contain stroke color");
+        }
+
+        @Test
+        void testRectangleNeitherFilledNorStroked() {
+            SRectangle rect = SRectangle.create(0, 0, 30, 30);
+            rect.addAttributes(new ColorAttributes(false, false, Color.RED, Color.BLUE));
+            draftman.visitRectangle(rect);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"none\""), "Should have fill=none");
+            assertFalse(svg.contains("stroke="), "Should not have stroke attribute");
+        }
+    }
+
+    // ── visitCircle ─────────────────────────────────────────────────
+
+    @Nested
+    class VisitCircleTests {
+
+        @Test
+        void testCircleElementWithCorrectAttributes() {
+            SCircle circle = SCircle.create(50, 60, 30);
+            draftman.visitCircle(circle);
+
+            String svg = output();
+            assertTrue(svg.contains("<circle"), "Should produce a <circle> element");
+            // cx = x + r = 50 + 30 = 80, cy = y + r = 60 + 30 = 90
+            assertTrue(svg.contains("cx=\"80\""), "cx should be x + radius");
+            assertTrue(svg.contains("cy=\"90\""), "cy should be y + radius");
+            assertTrue(svg.contains("r=\"30\""), "Should have correct radius");
+        }
+
+        @Test
+        void testCircleFilledOnly() {
+            SCircle circle = SCircle.create(0, 0, 20);
+            circle.addAttributes(new ColorAttributes(true, false, Color.GREEN, Color.BLACK));
+            draftman.visitCircle(circle);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#00ff00\""), "Should contain fill color");
+            assertFalse(svg.contains("stroke="), "Should not contain stroke");
+        }
+
+        @Test
+        void testCircleStrokedOnly() {
+            SCircle circle = SCircle.create(0, 0, 20);
+            circle.addAttributes(new ColorAttributes(false, true, Color.RED, Color.MAGENTA));
+            draftman.visitCircle(circle);
+
+            String svg = output();
+            assertTrue(svg.contains("stroke=\"#ff00ff\""), "Should contain stroke color");
+            assertTrue(svg.contains("fill=\"none\""), "Should have fill=none");
+        }
+
+        @Test
+        void testCircleFilledAndStroked() {
+            SCircle circle = SCircle.create(0, 0, 15);
+            circle.addAttributes(new ColorAttributes(true, true, Color.YELLOW, Color.BLACK));
+            draftman.visitCircle(circle);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#ffff00\""), "Should contain fill color");
+            assertTrue(svg.contains("stroke=\"#000000\""), "Should contain stroke color");
+        }
+    }
+
+    // ── visitTriangle ───────────────────────────────────────────────
+
+    @Nested
+    class VisitTriangleTests {
+
+        @Test
+        void testTriangleProducesPolygonElement() {
+            STriangle tri = STriangle.create(10, 20, 40, Color.RED, Color.BLACK);
+            draftman.visitTriangle(tri);
+
+            String svg = output();
+            assertTrue(svg.contains("<polygon"), "Should produce a <polygon> element");
+            assertTrue(svg.contains("points="), "Should have points attribute");
+        }
+
+        @Test
+        void testTrianglePointsAreCorrect() {
+            STriangle tri = STriangle.create(10, 20, 40, Color.RED, Color.BLACK);
+            draftman.visitTriangle(tri);
+
+            String svg = output();
+            // bottom-left: (x, y+size) = (10, 60)
+            assertTrue(svg.contains("10,60"), "Should contain bottom-left point");
+            // top-center: (x + size/2, y) = (30, 20)
+            assertTrue(svg.contains("30,20"), "Should contain top-center point");
+            // bottom-right: (x + size, y + size) = (50, 60)
+            assertTrue(svg.contains("50,60"), "Should contain bottom-right point");
+        }
+
+        @Test
+        void testTriangleFilledOnly() {
+            STriangle tri = STriangle.create(0, 0, 20, Color.BLUE, Color.BLACK);
+            tri.addAttributes(new ColorAttributes(true, false, Color.BLUE, Color.BLACK));
+            draftman.visitTriangle(tri);
+
+            String svg = output();
+            assertTrue(svg.contains("fill:#0000ff"), "Should contain fill style");
+            assertFalse(svg.contains("stroke:"), "Should not contain stroke style when not stroked");
+        }
+
+        @Test
+        void testTriangleStrokedAndFilled() {
+            STriangle tri = STriangle.create(0, 0, 20, Color.RED, Color.GREEN);
+            tri.addAttributes(new ColorAttributes(true, true, Color.RED, Color.GREEN));
+            draftman.visitTriangle(tri);
+
+            String svg = output();
+            assertTrue(svg.contains("fill:#ff0000"), "Should contain fill style");
+            assertTrue(svg.contains("stroke:#00ff00"), "Should contain stroke style");
+        }
+
+        @Test
+        void testTriangleNotFilled() {
+            STriangle tri = STriangle.create(0, 0, 20, Color.RED, Color.BLACK);
+            tri.addAttributes(new ColorAttributes(false, true, Color.RED, Color.BLACK));
+            draftman.visitTriangle(tri);
+
+            String svg = output();
+            assertTrue(svg.contains("fill:none"), "Should have fill:none when not filled");
+        }
+    }
+
+    // ── visitText ───────────────────────────────────────────────────
+
+    @Nested
+    class VisitTextTests {
+
+        @Test
+        void testTextElementWithCorrectContent() {
+            SText text = SText.create(10, 20, "Hello");
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("<text"), "Should produce a <text> element");
+            assertTrue(svg.contains(">Hello</text>"), "Should contain the text content");
+        }
+
+        @Test
+        void testTextPositionIncludesFontSizeOffset() {
+            SText text = SText.create(10, 20, "Hi");
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("x=\"10\""), "x should match bounds.x");
+            // y = bounds.y + fontSize = 20 + 16 = 36
+            assertTrue(svg.contains("y=\"36\""), "y should be bounds.y + fontSize");
+        }
+
+        @Test
+        void testTextDefaultFontAttributes() {
+            SText text = SText.create(0, 0, "Test");
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("font-family=\"SansSerif\""), "Should use default font family");
+            assertTrue(svg.contains("font-size=\"16\""), "Should use default font size");
+            assertTrue(svg.contains("font-style=\"normal\""), "Default style should be normal");
+            assertTrue(svg.contains("font-weight=\"normal\""), "Default weight should be normal");
+        }
+
+        @Test
+        void testTextDefaultColorIsBlack() {
+            SText text = SText.create(0, 0, "Test");
+            // default ColorAttributes: filled=true, filledColor=BLACK
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#000000\""), "Default text color should be black");
+        }
+
+        @Test
+        void testTextWithCustomFillColor() {
+            SText text = SText.create(0, 0, "Colored");
+            text.addAttributes(new ColorAttributes(true, false, Color.RED, Color.BLACK));
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#ff0000\""), "Text should use filledColor");
+        }
+
+        @Test
+        void testTextWithNullColorAttributesFallsBackToBlack() {
+            SText text = SText.create(0, 0, "NoColor");
+            text.addAttributes(new ColorAttributes(false, false, null, null));
+            draftman.visitText(text);
+
+            String svg = output();
+            assertTrue(svg.contains("fill=\"#000000\""), "Should fall back to black with null colors");
+        }
+    }
+
+    // ── visitCollection ─────────────────────────────────────────────
+
+    @Nested
+    class VisitCollectionTests {
+
+        @Test
+        void testEmptyCollection() {
+            SCollection empty = SCollection.of();
+            draftman.visitCollection(empty);
+
+            String svg = output();
+            assertEquals("", svg, "Empty collection should produce no output");
+        }
+
+        @Test
+        void testCollectionVisitsAllChildren() {
+            SCollection coll = SCollection.of(
+                    SRectangle.create(0, 0, 10, 10),
+                    SCircle.create(20, 20, 5)
+            );
+            draftman.visitCollection(coll);
+
+            String svg = output();
+            assertTrue(svg.contains("<rect"), "Should visit rectangle");
+            assertTrue(svg.contains("<circle"), "Should visit circle");
+        }
+
+        @Test
+        void testNestedCollectionVisitsAllDescendants() {
+            SCollection inner = SCollection.of(
+                    SRectangle.create(0, 0, 5, 5)
+            );
+            SCollection outer = SCollection.of(
+                    inner,
+                    SCircle.create(10, 10, 3)
+            );
+            draftman.visitCollection(outer);
+
+            String svg = output();
+            assertTrue(svg.contains("<rect"), "Should visit nested rectangle");
+            assertTrue(svg.contains("<circle"), "Should visit circle at outer level");
+        }
+    }
+
+    // ── generateSVG ─────────────────────────────────────────────────
+
+    @Nested
+    class GenerateSVGTests {
+
+        @Test
+        void testGenerateSVGIncludesXmlDeclaration() {
+            SCollection model = SCollection.of();
+            draftman.generateSVG(model);
+
+            String svg = output();
+            assertTrue(svg.contains("<?xml version=\"1.0\" encoding=\"utf-8\"?>"),
+                    "Should include XML declaration");
+        }
+
+        @Test
+        void testGenerateSVGIncludesSvgNamespace() {
+            SCollection model = SCollection.of();
+            draftman.generateSVG(model);
+
+            String svg = output();
+            assertTrue(svg.contains("xmlns=\"http://www.w3.org/2000/svg\""),
+                    "Should include SVG namespace");
+        }
+
+        @Test
+        void testGenerateSVGClosesSvgTag() {
+            SCollection model = SCollection.of();
+            draftman.generateSVG(model);
+
+            String svg = output();
+            assertTrue(svg.contains("</svg>"), "Should close <svg> tag");
+        }
+
+        @Test
+        void testGenerateSVGIncludesShapeContent() {
+            SCollection model = SCollection.of(
+                    SRectangle.create(1, 2, 3, 4)
+            );
+            draftman.generateSVG(model);
+
+            String svg = output();
+            assertTrue(svg.contains("<rect"), "Should include shape elements");
+            assertTrue(svg.contains("</svg>"), "Should close SVG after shapes");
+        }
+    }
+}