better implicit bar/rect position (#1552)

Author: mbostock

src/marks/bar.js

@@ -1,15 +1,9 @@
 import {create} from "../context.js";
 import {Mark} from "../mark.js";
-import {identity, indexOf, number} from "../options.js";
+import {hasXY, identity, indexOf, number} from "../options.js";
 import {isCollapsed} from "../scales.js";
-import {
-  applyDirectStyles,
-  applyIndirectStyles,
-  applyTransform,
-  impliedString,
-  applyAttr,
-  applyChannelStyles
-} from "../style.js";
+import {applyAttr, applyChannelStyles, applyDirectStyles, applyIndirectStyles, applyTransform} from "../style.js";
+import {impliedString} from "../style.js";
 import {maybeIdentityX, maybeIdentityY} from "../transforms/identity.js";
 import {maybeIntervalX, maybeIntervalY} from "../transforms/interval.js";
 import {maybeStackX, maybeStackY} from "../transforms/stack.js";
@@ -129,10 +123,12 @@ export class BarY extends AbstractBar {
   }
 }
 
-export function barX(data, options = {y: indexOf, x2: identity}) {
+export function barX(data, options = {}) {
+  if (!hasXY(options)) options = {...options, y: indexOf, x2: identity};
   return new BarX(data, maybeStackX(maybeIntervalX(maybeIdentityX(options))));
 }
 
-export function barY(data, options = {x: indexOf, y2: identity}) {
+export function barY(data, options = {}) {
+  if (!hasXY(options)) options = {...options, x: indexOf, y2: identity};
   return new BarY(data, maybeStackY(maybeIntervalY(maybeIdentityY(options))));
 }

src/marks/rect.js

@@ -1,15 +1,9 @@
 import {create} from "../context.js";
 import {Mark} from "../mark.js";
-import {identity, indexOf, number} from "../options.js";
+import {hasXY, identity, indexOf, number} from "../options.js";
 import {isCollapsed} from "../scales.js";
-import {
-  applyDirectStyles,
-  applyIndirectStyles,
-  applyTransform,
-  impliedString,
-  applyAttr,
-  applyChannelStyles
-} from "../style.js";
+import {applyAttr, applyChannelStyles, applyDirectStyles, applyIndirectStyles, applyTransform} from "../style.js";
+import {impliedString} from "../style.js";
 import {maybeIdentityX, maybeIdentityY} from "../transforms/identity.js";
 import {maybeTrivialIntervalX, maybeTrivialIntervalY} from "../transforms/interval.js";
 import {maybeStackX, maybeStackY} from "../transforms/stack.js";
@@ -103,10 +97,12 @@ export function rect(data, options) {
   return new Rect(data, maybeTrivialIntervalX(maybeTrivialIntervalY(options)));
 }
 
-export function rectX(data, options = {y: indexOf, interval: 1, x2: identity}) {
+export function rectX(data, options = {}) {
+  if (!hasXY(options)) options = {...options, y: indexOf, x2: identity, interval: 1};
   return new Rect(data, maybeStackX(maybeTrivialIntervalY(maybeIdentityX(options))));
 }
 
-export function rectY(data, options = {x: indexOf, interval: 1, y2: identity}) {
+export function rectY(data, options = {}) {
+  if (!hasXY(options)) options = {...options, x: indexOf, y2: identity, interval: 1};
   return new Rect(data, maybeStackY(maybeTrivialIntervalX(maybeIdentityY(options))));
 }

src/options.js

@@ -139,6 +139,21 @@ export function slice(values, type = Array) {
   return values instanceof type ? values.slice() : type.from(values);
 }
 
+// Returns true if any of x, x1, or x2 is not (strictly) undefined.
+export function hasX({x, x1, x2}) {
+  return x !== undefined || x1 !== undefined || x2 !== undefined;
+}
+
+// Returns true if any of y, y1, or y2 is not (strictly) undefined.
+export function hasY({y, y1, y2}) {
+  return y !== undefined || y1 !== undefined || y2 !== undefined;
+}
+
+// Returns true if has x or y, or if interval is not (strictly) undefined.
+export function hasXY(options) {
+  return hasX(options) || hasY(options) || options.interval !== undefined;
+}
+
 // Disambiguates an options object (e.g., {y: "x2"}) from a primitive value.
 export function isObject(option) {
   return option?.toString === objectToString;

src/transforms/identity.js

@@ -1,11 +1,9 @@
-import {identity} from "../options.js";
+import {hasX, hasY, identity} from "../options.js";
 
 export function maybeIdentityX(options = {}) {
-  const {x, x1, x2} = options;
-  return x1 === undefined && x2 === undefined && x === undefined ? {...options, x: identity} : options;
+  return hasX(options) ? options : {...options, x: identity};
 }
 
 export function maybeIdentityY(options = {}) {
-  const {y, y1, y2} = options;
-  return y1 === undefined && y2 === undefined && y === undefined ? {...options, y: identity} : options;
+  return hasY(options) ? options : {...options, y: identity};
 }