fix LIBSVM model type mapping

didn't quite understand why it didn't work before but works now

src/LIBSVM.jl

@@ -279,6 +279,32 @@ function EpsilonSVR(
 end
 
 
+const SVM = Union{LinearSVC, SVC, NuSVC, NuSVR, EpsilonSVR, OneClassSVM} # all SVM models defined here
+
+
+"""
+    map_model_type(model::SVM)
+
+Helper function to map the model to the correct LIBSVM model type needed for function dispatch.
+"""
+function map_model_type(model::SVM)
+    if isa(model, LinearSVC)
+        return LIBSVM.LinearSVC
+    elseif isa(model, SVC)
+        return LIBSVM.SVC
+    elseif isa(model, NuSVC)
+        return LIBSVM.NuSVC
+    elseif isa(model, NuSVR)
+        return LIBSVM.NuSVR
+    elseif isa(model, EpsilonSVR)
+        return LIBSVM.EpsilonSVR
+    elseif isa(model, OneClassSVM)
+        return LIBSVM.OneClassSVM
+    else
+        error("Got unsupported model type: $(typeof(model))")
+    end
+end
+
 """
     get_svm_parameters(model::Union{SVC, NuSVC, NuSVR, EpsilonSVR, OneClassSVM})
 
@@ -287,7 +313,7 @@ Helper function to get the parameters from the SVM model struct.
 function get_svm_parameters(model::Union{SVC, NuSVC, NuSVR, EpsilonSVR, OneClassSVM})
     #Build arguments for calling svmtrain
     params = Tuple{Symbol, Any}[]
-    push!(params, (:svmtype, eval(Meta.parse("LIBSVM.$(typeof(model))")))) # LIBSVM model type
+    push!(params, (:svmtype, map_model_type(model))) # get LIBSVM model type
     for fn in fieldnames(typeof(model))
         push!(params, (fn, getfield(model, fn)))
     end
@@ -402,7 +428,6 @@ MLJBase.load_path(::Type{<:NuSVR}) = "MLJModels.LIBSVM_.NuSVR"
 MLJBase.load_path(::Type{<:EpsilonSVR}) = "MLJModels.LIBSVM_.EpsilonSVR"
 MLJBase.load_path(::Type{<:OneClassSVM}) = "MLJModels.LIBSVM_.OneClassSVM"
 
-const SVM = Union{LinearSVC, SVC, NuSVC, NuSVR, EpsilonSVR, OneClassSVM} # all SVM models defined here
 MLJBase.package_name(::Type{<:SVM}) = "LIBSVM"
 MLJBase.package_uuid(::Type{<:SVM}) = "b1bec4e5-fd48-53fe-b0cb-9723c09d164b"
 MLJBase.is_pure_julia(::Type{<:SVM}) = false

test/LIBSVM.jl

@@ -4,6 +4,7 @@ using MLJBase
 using Test
 using LinearAlgebra
 
+import MLJModels
 import LIBSVM 
 using MLJModels.LIBSVM_
 using CategoricalArrays