s2: Move earth radius constant to common test constant.

Signed-off-by: David Symonds <dsymonds@golang.org>

Author: rsned

s2/point_test.go

@@ -39,8 +39,6 @@ func TestOriginPoint(t *testing.T) {
 	}
 
 	// Check that the origin is not too close to either pole.
-	// The Earth's mean radius in kilometers (according to NASA).
-	const earthRadiusKm = 6371.01
 	if dist := math.Acos(OriginPoint().Z) * earthRadiusKm; dist <= 50 {
 		t.Errorf("Origin point is to close to the North Pole. Got %v, want >= 50km", dist)
 	}

s2/predicates_test.go

@@ -227,7 +227,6 @@ func TestPredicatesRobustSign(t *testing.T) {
 }
 
 func TestPredicatesStableSignFailureRate(t *testing.T) {
-	const earthRadiusKm = 6371.01
 	const iters = 1000
 
 	// Verify that stableSign is able to handle most cases where the three

s2/s2_test.go

@@ -42,10 +42,11 @@ func float64Near(x, y, ε float64) bool {
 
 // TODO(roberts): Add in flag to allow specifying the random seed for repeatable tests.
 
+// The Earth's mean radius in kilometers (according to NASA).
+const earthRadiusKm = 6371.01
+
 // kmToAngle converts a distance on the Earth's surface to an angle.
 func kmToAngle(km float64) s1.Angle {
-	// The Earth's mean radius in kilometers (according to NASA).
-	const earthRadiusKm = 6371.01
 	return s1.Angle(km / earthRadiusKm)
 }
 

s2/s2_test_test.go

@@ -23,8 +23,6 @@ import (
 )
 
 func TestKmToAngle(t *testing.T) {
-	const earthRadiusKm = 6371.01
-
 	tests := []struct {
 		have float64
 		want s1.Angle