minBarLength at base going both ways (#7642)

src/controllers/controller.bar.js

@@ -409,7 +409,7 @@ export default class BarController extends DatasetController {
 		// So we don't try to draw so huge rectangles.
 		// https://github.com/chartjs/Chart.js/issues/5247
 		// TODO: use borderWidth instead (need to move the parsing from rectangle)
-		const base = _limitValue(vScale.getPixelForValue(start),
+		let base = _limitValue(vScale.getPixelForValue(start),
 			vScale._startPixel - 10,
 			vScale._endPixel + 10);
 
@@ -418,6 +418,9 @@ export default class BarController extends DatasetController {
 
 		if (minBarLength !== undefined && Math.abs(size) < minBarLength) {
 			size = size < 0 ? -minBarLength : minBarLength;
+			if (value === 0) {
+				base -= size / 2;
+			}
 			head = base + size;
 		}
 

test/fixtures/controller.bar/minBarLength/horizontal-neg.js

@@ -0,0 +1,35 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2],
+			datasets: [
+				{
+					data: [0, -0.01, -30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			indexAxis: 'y',
+			scales: {
+				x: {
+					ticks: {
+						display: false
+					}
+				},
+				y: {display: false}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};

test/fixtures/controller.bar/minBarLength/horizontal-pos.js

@@ -0,0 +1,35 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2],
+			datasets: [
+				{
+					data: [0, 0.01, 30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			indexAxis: 'y',
+			scales: {
+				x: {
+					ticks: {
+						display: false
+					}
+				},
+				y: {display: false}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};

test/fixtures/controller.bar/minBarLength/horizontal.js

@@ -0,0 +1,35 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2, 3, 4],
+			datasets: [
+				{
+					data: [0, -0.01, 0.01, 30, -30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			indexAxis: 'y',
+			scales: {
+				x: {
+					ticks: {
+						display: false
+					}
+				},
+				y: {display: false}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};

test/fixtures/controller.bar/minBarLength/vertical-neg.js

@@ -0,0 +1,34 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2],
+			datasets: [
+				{
+					data: [0, -0.01, -30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			scales: {
+				x: {display: false},
+				y: {
+					ticks: {
+						display: false
+					}
+				}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};

test/fixtures/controller.bar/minBarLength/vertical-pos.js

@@ -0,0 +1,34 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2],
+			datasets: [
+				{
+					data: [0, 0.01, 30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			scales: {
+				x: {display: false},
+				y: {
+					ticks: {
+						display: false
+					}
+				}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};

test/fixtures/controller.bar/minBarLength/vertical.js

@@ -0,0 +1,34 @@
+module.exports = {
+	config: {
+		type: 'bar',
+		data: {
+			labels: [0, 1, 2, 3, 4],
+			datasets: [
+				{
+					data: [0, -0.01, 0.01, 30, -30],
+					backgroundColor: '#00ff00',
+					borderWidth: 0,
+					minBarLength: 20
+				}
+			]
+		},
+		options: {
+			legend: false,
+			title: false,
+			scales: {
+				x: {display: false},
+				y: {
+					ticks: {
+						display: false
+					}
+				}
+			}
+		}
+	},
+	options: {
+		canvas: {
+			height: 512,
+			width: 512
+		}
+	}
+};