test: test get_new_mm

Author: AayushSabharwal

test/runtests.jl

@@ -1,4 +1,31 @@
 using StateSelection
+import StateSelection as SSel
+using SparseArrays
 using Test
 
 include("bareiss.jl")
+
+@testset "`get_new_mm`" begin
+    mm = SSel.CLIL.SparseMatrixCLIL(
+        [
+            -1 0 2 0
+            2 1 2 0
+            0 0 1 2
+        ]
+    )
+    # We're using the first equation to solve for the first variable,
+    # and removing the last variable (assuming it's torn via some other
+    # equation)
+    old_to_new_eq = [0, 2, 3]
+    old_to_new_var = [0, 1, 2, 0]
+    aliases = Dict(1 => sparse([0, 0, 2, 0]))
+    mm2 = SSel.get_new_mm(aliases, old_to_new_eq, old_to_new_var, mm)
+    # Eq#3 can't be retained, because it depends on variable 4 which isn't an
+    # integer coefficient linear combination
+    @test mm2.nzrows == [2]
+    @test mm2.row_cols == [[1, 2]]
+    @test mm2.row_vals == [[1, 6]]
+    @test mm2.ncols == 2
+    aliases = Dict(1 => sparse([0, 0, 2, 1]))
+    @test_throws SSel.BadMMAliasError SSel.get_new_mm(aliases, old_to_new_eq, old_to_new_var, mm)
+end