diff --git a/test/dict.jl b/test/dict.jl
index 525e75c2495b0..6c5a730a7fff8 100644
--- a/test/dict.jl
+++ b/test/dict.jl
@@ -467,10 +467,16 @@ end
     @test_throws MethodError d[1] = :a
 
     # copy constructor
-    d = IdDict{Int,Int}(Pair(1,1), Pair(2,2), Pair(3,3))
+    d = IdDict(Pair(1,1), Pair(2,2), Pair(3,3))
     @test collect(values(IdDict{Int,Float64}(d))) == collect(values(d))
     @test_throws ArgumentError IdDict{Float64,Int}(d)
 
+    # misc constructors
+    @test typeof(IdDict(1=>1, :a=>2)) == IdDict{Any,Int}
+    @test typeof(IdDict(1=>1, 1=>:a)) == IdDict{Int,Any}
+    @test typeof(IdDict(:a=>1, 1=>:a)) == IdDict{Any,Any}
+    @test typeof(IdDict(())) == IdDict{Any,Any}
+
     # check that returned values are inferred
     d = @inferred IdDict(Pair(1,1), Pair(2,2), Pair(3,3))
     @test 1 == @inferred d[1]
@@ -484,6 +490,31 @@ end
     i = @inferred start(d)
     @inferred next(d, i)
     @inferred done(d, i)
+
+    # get! and delete!
+    d = @inferred IdDict(Pair(:a,1), Pair(:b,2), Pair(3,3))
+    @test get!(d, "a", -1) == -1
+    @test d["a"] == -1
+    @test get!(d, "a", "b") == -1
+    @test_throws MethodError get!(d, "b", "b")
+    @test delete!(d, "a") === d
+    @test !haskey(d, "a")
+    @test_throws ArgumentError get!(IdDict{Symbol,Any}(), 2, "b")
+
+
+    # sizehint! & rehash!
+    d = IdDict()
+    @test sizehint!(d, 10^4) === d
+    @test length(d.ht) >= 10^4
+    d = IdDict()
+    for jj=1:30, i=1:10^4
+        d[i] = i
+    end
+    for i=1:10^4
+        @test d[i] == i
+    end
+    @test length(d.ht) >= 10^4
+    @test d === Base.rehash!(d, 123452) # number needs to be even
 end