add tests for BigFloat constructor, nextfloat and prevfloat

test/mpfr.jl

@@ -44,11 +44,20 @@ import Base.MPFR
         setprecision(prec) do
             @test precision(xs[end]) != prec
             for x in xs
-                @test precision(BigFloat(x)) == prec
                 @test precision(BigFloat(x; precision=prec ÷ 2)) == prec ÷ 2
             end
+            @test precision(BigFloat(12.12)) == prec
         end
     end
+
+    # test for new BigFloat constructor
+    a = BigFloat(pi, precision=100)
+    b = BigFloat(a)
+    @test a === b
+    b = BigFloat(a, new=true)
+    @test a !== b && a == b
+    b = BigFloat(a, precision=128)
+    @test a !== b && a == b && precision(b) == 128
 end
 @testset "basic arithmetic" begin
     tol = 1e-12
@@ -444,8 +453,23 @@ end
     @test x == y
     nextfloat(y)
     @test x == y
+    z = BigFloat(y, new=true)
+    nextfloat!(z)
+    @test z != y && z == nextfloat(y)
+    y = BigFloat(x)
+    @test x == y
     prevfloat(y)
     @test x == y
+    z = BigFloat(y, new=true)
+    prevfloat!(z)
+    @test z != y && z == prevfloat(y)
+    x = BigFloat(12.12)
+    @test nextfloat(x, 0) !== x && nextfloat(x, 0) == x
+    @test nextfloat(x, 1) == nextfloat(x)
+    @test prevfloat(x, 0) !== x && prevfloat(x, 0) == x
+    @test prevfloat(x, 1) == prevfloat(x)
+    @test nextfloat(x, -1) == prevfloat(x, 1)
+    @test prevfloat(x, -1) == nextfloat(x, 1)
     setprecision(53) do
         x = BigFloat(12.12)
         @test BigFloat(nextfloat(12.12)) == nextfloat(x)