toBeCloseTo treats Infinity and -Infinity as close to themselves

* Fixes #1957

lib/jasmine-core/jasmine.js

@@ -5961,6 +5961,14 @@ getJasmineRequireObj().toBeCloseTo = function() {
           );
         }
 
+        // Infinity is close to Infinity and -Infinity is close to -Infinity,
+        // regardless of the precision.
+        if (expected === Infinity || expected === -Infinity) {
+          return {
+            pass: actual === expected
+          };
+        }
+
         var pow = Math.pow(10, precision + 1);
         var delta = Math.abs(expected - actual);
         var maxDelta = Math.pow(10, -precision) / 2;

spec/core/matchers/toBeCloseToSpec.js

@@ -110,4 +110,42 @@ describe('toBeCloseTo', function() {
     result = matcher.compare(-2.82665525779431, -2.82666, 5);
     expect(result.pass).toBe(true);
   });
+
+  describe('Infinity handling', function() {
+    it('passes when the actual and expected are both Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(Infinity, Infinity, 0);
+      expect(result.pass).toBe(true);
+    });
+
+    it('passes when the actual and expected are both -Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(-Infinity, -Infinity, 0);
+      expect(result.pass).toBe(true);
+    });
+
+    it('fails when the actual is Infinity and the expected is -Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(Infinity, -Infinity, 0);
+      expect(result.pass).toBe(false);
+    });
+
+    it('fails when the actual is -Infinity and the expected is Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(-Infinity, Infinity, 0);
+      expect(result.pass).toBe(false);
+    });
+
+    it('fails when the actual is a number and the expected is Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(42, Infinity, 0);
+      expect(result.pass).toBe(false);
+    });
+
+    it('fails when the actual is a number and the expected is -Infinity', function() {
+      const matcher = jasmineUnderTest.matchers.toBeCloseTo();
+      const result = matcher.compare(42, -Infinity, 0);
+      expect(result.pass).toBe(false);
+    });
+  });
 });

src/core/matchers/toBeCloseTo.js

@@ -27,6 +27,14 @@ getJasmineRequireObj().toBeCloseTo = function() {
           );
         }
 
+        // Infinity is close to Infinity and -Infinity is close to -Infinity,
+        // regardless of the precision.
+        if (expected === Infinity || expected === -Infinity) {
+          return {
+            pass: actual === expected
+          };
+        }
+
         var pow = Math.pow(10, precision + 1);
         var delta = Math.abs(expected - actual);
         var maxDelta = Math.pow(10, -precision) / 2;