test: add some latex tests (#5)

Author: oameye

src/display.jl

@@ -248,7 +248,7 @@ function latex(term::Term; advanced::Bool=true)
         result *= "e^{im_1\\omega t}"
     end
 
-    return result
+    return latexstring(result)
 end
 
 """

test/display.jl

@@ -9,11 +9,22 @@ Tests for LaTeX generation and display functionality.
         latex_str = latex(term; advanced=false)  # Use simple format for this test
         @test isa(latex_str, LaTeXString)
         @test occursin("2*1", latex_str)
+
+        latex_str = latex(term; advanced=true)
+        @test isa(latex_str, LaTeXString)
+        @test occursin("H_{m_1}", latex_str)
     end
 
     @testset "Terms Collection LaTeX" begin
         terms = Terms([Term(rotating=0), Term(rotating=1)])
         latex_str = latex(terms; advanced=false) # Use simple format for this test
         @test isa(latex_str, LaTeXString)
+        @test occursin("1*0", latex_str)
+        @test occursin("1*1", latex_str)
+
+        latex_str = latex(terms; advanced=true)
+        @test isa(latex_str, LaTeXString)
+        @test occursin("H_0", latex_str)
+        @test occursin("H_{m_1}", latex_str)
     end
 end