Merge pull request #215 from rotaready/intersect-zero-length-ranges

Correctly intersect zero-length ranges
rotaready · Jan 19, 2018 · 8c58310 · 8c58310
2 parents 5b062de + 6a6a35c
commit 8c58310
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+## [3.1.1]
+### Fixed
+* Fixed intersection rules for zero-length ranges on start/end boundaries
+
 ## [3.1.0]
 ### Added
 

diff --git a/lib/moment-range.js b/lib/moment-range.js
@@ -154,19 +154,44 @@ export class DateRange {
   intersect(other) {
     const start = this.start.valueOf();
     const end = this.end.valueOf();
-    const oStart = other.start.valueOf();
-    const oEnd = other.end.valueOf();
+    const otherStart = other.start.valueOf();
+    const otherEnd = other.end.valueOf();
+    const isZeroLength = (start == end);
+    const isOtherZeroLength = (otherStart == otherEnd);
+
+    // Zero-length ranges
+    if (isZeroLength) {
+      const point = start;
+
+      if ((point == otherStart) || (point == otherEnd)) {
+        return null;
+      }
+      else if ((point > otherStart) && (point < otherEnd)) {
+        return this;
+      }
+    }
+    else if (isOtherZeroLength) {
+      const point = otherStart;
+
+      if ((point == start) || (point == end)) {
+        return null;
+      }
+      else if ((point > start) && (point < end)) {
+        return other;
+      }
+    }
 
-    if ((start <= oStart) && (oStart < end) && (end < oEnd)) {
-      return new this.constructor(oStart, end);
+    // Non zero-length ranges
+    if ((start <= otherStart) && (otherStart < end) && (end < otherEnd)) {
+      return new this.constructor(otherStart, end);
     }
-    else if ((oStart < start) && (start < oEnd) && (oEnd <= end)) {
-      return new this.constructor(start, oEnd);
+    else if ((otherStart < start) && (start < otherEnd) && (otherEnd <= end)) {
+      return new this.constructor(start, otherEnd);
     }
-    else if ((oStart < start) && (start <= end) && (end < oEnd)) {
+    else if ((otherStart < start) && (start <= end) && (end < otherEnd)) {
       return this;
     }
-    else if ((start <= oStart) && (oStart <= oEnd) && (oEnd <= end)) {
+    else if ((start <= otherStart) && (otherStart <= otherEnd) && (otherEnd <= end)) {
       return other;
     }
 

diff --git a/lib/moment-range_test.js b/lib/moment-range_test.js
@@ -750,6 +750,44 @@ describe('DateRange', function() {
       expect(range1.overlaps(range2, { adjacent: false })).to.be(false);
       expect(range1.overlaps(range2, { adjacent: true })).to.be(true);
     });
+
+    it('should not overlap zero-length ranges on the start date when `adjacent` is `false`', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const range1 = moment.range(a, a);
+      const range2 = moment.range(a, b);
+
+      expect(range1.overlaps(range2)).to.be(false);
+      expect(range1.overlaps(range2, { adjacent: false })).to.be(false);
+    });
+
+    it('should overlap zero-length ranges on the start date when `adjacent` is `true`', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const range1 = moment.range(a, a);
+      const range2 = moment.range(a, b);
+
+      expect(range1.overlaps(range2, { adjacent: true })).to.be(true);
+    });
+
+    it('should not overlap zero-length ranges on the end date when `adjacent` is `false`', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const range1 = moment.range(a, b);
+      const range2 = moment.range(b, b);
+
+      expect(range1.overlaps(range2)).to.be(false);
+      expect(range1.overlaps(range2, { adjacent: false })).to.be(false);
+    });
+
+    it('should overlap zero-length ranges on the end date when `adjacent` is `true`', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const range1 = moment.range(a, b);
+      const range2 = moment.range(b, b);
+
+      expect(range1.overlaps(range2, { adjacent: true })).to.be(true);
+    });
   });
 
   describe('#intersect()', function() {
@@ -854,6 +892,42 @@ describe('DateRange', function() {
 
       expect(dr1.intersect(dr2).isSame(dr1)).to.be(true);
     });
+
+    it('should return `null` with [---{}] non-overlaps where (a=[], b={})', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const dr1 = moment.range(a, b);
+      const dr2 = moment.range(b, b);
+
+      expect(dr1.intersect(dr2)).to.be(null);
+    });
+
+    it('should return `null` with [{}---] non-overlaps where (a=[], b={})', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const dr1 = moment.range(a, b);
+      const dr2 = moment.range(a, a);
+
+      expect(dr1.intersect(dr2)).to.be(null);
+    });
+
+    it('should return `null` with {---[]} non-overlaps where (a=[], b={})', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const dr1 = moment.range(b, b);
+      const dr2 = moment.range(a, b);
+
+      expect(dr1.intersect(dr2)).to.be(null);
+    });
+
+    it('should return `null` with {[]---} non-overlaps where (a=[], b={})', function() {
+      const a = moment.utc('2018-02-01T03:00:00');
+      const b = moment.utc('2018-02-01T13:00:00');
+      const dr1 = moment.range(a, a);
+      const dr2 = moment.range(a, b);
+
+      expect(dr1.intersect(dr2)).to.be(null);
+    });
   });
 
   describe('#add()', function() {