Merge pull request #6 from JuliaGeo/better_convert

clarify convert for mixed, improve tests and bump version to 0.3

Author: rafaqz

Project.toml

@@ -1,7 +1,7 @@
 name = "GeoFormatTypes"
 uuid = "68eda718-8dee-11e9-39e7-89f7f65f511f"
 authors = ["Rafael Schouten <rafaelschouten@gmail.com>"]
-version = "0.2.1"
+version = "0.3.0"
 
 [compat]
 julia = "1"

src/GeoFormatTypes.jl

@@ -43,18 +43,27 @@ abstract type GeoFormat end
 Base.convert(::Type{T1}, source::T2) where {T1<:GeoFormat,T2<:T1} = source
 # Convert uses the `mode` trait to distinguish crs form geometry conversion
 Base.convert(target::Type{T1}, source::T2) where {T1<:GeoFormat,T2<:GeoFormat} = begin
-    formatmode = mode(source)
+    sourcemode = mode(source)
     targetmode = mode(target)
-    convertmode = if formatmode isa Mixed
-        if targetmode isa Mixed
+    convertmode = if targetmode isa Geom
+        if sourcemode isa Union{Mixed,Geom}
             Geom() # Geom is the default if both formats are mixed
         else
-            targetmode
+            throw(ArgumentError("cannot convert $(typeof(source)) to $target"))
+        end
+    elseif targetmode isa CRS
+        if sourcemode isa Union{Mixed,CRS}
+            CRS()
+        else
+            throw(ArgumentError("cannot convert $(typeof(source)) to $target"))
+        end
+    else # targetmode isa Mixed
+        # Mixed to Mixed defaults to Geom
+        if sourcemode isa Union{Mixed,Geom}
+            Geom()
+        else
+            CRS()
         end
-    elseif targetmode isa typeof(formatmode)
-        formatmode
-    else
-        throw(ArgumentError("cannot convert $(typeof(source)) to $target"))
     end
     convert(target, convertmode, source)
 end
@@ -120,6 +129,7 @@ struct WellKnownText{X,T<:String} <: AbstractWellKnownText{X}
     mode::X
     val::T
 end
+WellKnownText(val) = WellKnownText(Mixed(), val)
 
 """
 Well known text v2 following the new OGC standard
@@ -128,6 +138,7 @@ struct WellKnownText2{X,T<:String} <: AbstractWellKnownText{X}
     mode::X
     val::T
 end
+WellKnownText2(val) = WellKnownText(Mixed(), val)
 
 """
 Well known text following the ESRI standard
@@ -144,6 +155,7 @@ struct WellKnownBinary{X,T} <: MixedFormat{X}
     mode::X
     val::T
 end
+WellKnownBinary(val) = WellKnownBinary(Mixed(), val)
 
 Base.convert(::Type{String}, input::WellKnownBinary) =
     error("`convert` to `String` is not defined for `WellKnownBinary`")
@@ -184,6 +196,7 @@ struct GML{X,T<:String} <: MixedFormat{X}
     mode::X
     val::T
 end
+GML(val) = GML(Mixed(), val)
 
 """
 GeoJSON String or Dict

test/runtests.jl

@@ -1,19 +1,66 @@
 using GeoFormatTypes, Test
 using GeoFormatTypes: Geom, CRS, Mixed
 
-@test_throws ArgumentError ProjString("+lat_ts=56.5 +ellps=GRS80")
-convert(String, ProjString("+proj=merc +lat_ts=56.5 +ellps=GRS80")) == "+proj=merc +lat_ts=56.5 +ellps=GRS80"
+@testset "Test construcors" begin
+    @test_throws ArgumentError ProjString("+lat_ts=56.5 +ellps=GRS80")
+    @test_throws ArgumentError EPSG("ERROR:4326")
+    @test EPSG("EPSG:4326") == EPSG(4326)
+end
 
-@test_throws ArgumentError EPSG("ERROR:4326")
-@test convert(String, EPSG("EPSG:4326")) == "EPSG:4326" 
-@test convert(String, EPSG(4326)) == "EPSG:4326" 
-@test convert(Int, EPSG("EPSG:4326")) == 4326 
+@testset "Test conversion to string or int" begin
+    @test convert(String, ProjString("+proj=test")) == "+proj=test"
+    @test convert(String, EPSG(4326)) == "EPSG:4326"
+    @test convert(Int, EPSG(4326)) == 4326
+    @test convert(String, WellKnownText("test")) == "test"
+    @test convert(String, WellKnownText2("test")) == "test"
+    @test convert(String, GML("test")) == "test"
+    @test convert(String, KML("test")) == "test"
+    @test convert(String, GeoJSON("test")) == "test"
+end
 
-@test convert(String, WellKnownText(Geom(), "test")) == "test"
-@test convert(String, WellKnownText2(CRS(), "test")) == "test"
-@test convert(String, ESRIWellKnownText(Geom(), "test")) == "test"
-@test convert(String, GML(Mixed(), "test")) == "test"
-@test convert(String, KML("test")) == "test"
-@test convert(String, GeoJSON("test")) == "test"
 
-@test_throws ArgumentError convert(KML, ProjString("+proj=test"))
+# `convert` placeholder methods
+Base.convert(target::Type{<:GeoFormat}, mode::Union{Geom,Type{Geom}}, source::GeoFormat) =
+    :geom
+Base.convert(target::Type{<:GeoFormat}, mode::Union{CRS,Type{CRS}}, source::GeoFormat) =
+    :crs
+
+@testset "Test convert mode allocation" begin
+    @testset "Test identical type is passed through unchanged" begin
+        @test convert(WellKnownText, WellKnownText(Mixed(), "test")) == WellKnownText(Mixed(), "test")
+        @test convert(ProjString, ProjString("+proj=test")) == ProjString("+proj=test")
+    end
+    @testset "Test conversions are assigned to crs or geom correctly" begin
+        @test convert(WellKnownText, WellKnownText2(CRS(), "test")) == :crs
+        @test convert(WellKnownText2, WellKnownText(CRS(), "test")) == :crs
+        @test convert(WellKnownBinary, WellKnownText(CRS(), "test")) == :crs
+        @test convert(ProjString, WellKnownText(CRS(), "test")) == :crs
+        @test convert(EPSG, ProjString("+proj=test")) == :crs
+        @test convert(CoordSys, ProjString("+proj=test")) == :crs
+
+        @test convert(GeoJSON, WellKnownText(Geom(), "test")) == :geom
+        @test convert(KML, WellKnownText(Geom(), "test")) == :geom
+        @test convert(GML, WellKnownText(Geom(), "test")) == :geom
+        @test convert(ESRIWellKnownText, WellKnownText(Geom(), "test")) == :geom
+        @test convert(WellKnownBinary, WellKnownText(Geom(), "test")) == :geom
+        @test convert(WellKnownText2, WellKnownText(Geom(), "test")) == :geom
+        @test convert(WellKnownText2, WellKnownText(Geom(), "test")) == :geom
+        @test convert(WellKnownText, WellKnownText2(Geom(), "test")) == :geom
+
+        @test convert(GeoJSON, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(KML, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(GML, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(ESRIWellKnownText, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(WellKnownBinary, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(WellKnownText2, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(WellKnownText2, WellKnownText(Mixed(), "test")) == :geom
+        @test convert(WellKnownText, WellKnownText2(Mixed(), "test")) == :geom
+    end
+    @testset "Test conversions that are not possible throw an error" begin
+        @test_throws ArgumentError convert(KML, ProjString("+proj=test"))
+        @test_throws ArgumentError convert(GeoJSON, ProjString("+proj=test"))
+        @test_throws ArgumentError convert(ProjString, WellKnownText(Geom(), "test"))
+        @test_throws ArgumentError convert(CoordSys, WellKnownText(Geom(), "test"))
+        @test_throws ArgumentError convert(EPSG, WellKnownText(Geom(), "test"))
+    end
+end