Add missing mesh modifier tests to mesh generators tests specs

closes idaholab#13814

test/tests/meshgenerators/block_deletion_generator/tests

@@ -34,4 +34,79 @@
       detail = 'blocks and assigning the new boundary even if the input mesh is not prepared.'
     []
   []
+
+  [delete]
+    requirement = "The system shall support removing elements including"
+
+    [block_deletion_test2]
+      type = 'Exodiff'
+      input = 'block_deletion_test2.i'
+      exodiff = 'block_deletion_test2_out.e'
+
+      detail = "a 3D concave subdomain;"
+    []
+    [block_deletion_test3]
+      type = 'Exodiff'
+      input = 'block_deletion_test3.i'
+      exodiff = 'block_deletion_test3_out.e'
+
+      detail = "a 2D interior subdomain;"
+    []
+    [block_deletion_test4]
+      type = 'Exodiff'
+      input = 'block_deletion_test4.i'
+      exodiff = 'block_deletion_test4_out.e'
+
+      detail = "a 3D interior subdomain;"
+    []
+    [block_deletion_test5]
+      type = 'Exodiff'
+      input = 'block_deletion_test5.i'
+      exodiff = 'block_deletion_test5_out.e'
+
+      detail = "a 2D non-concave subdomain;"
+    []
+    [block_deletion_test6]
+      type = 'Exodiff'
+      input = 'block_deletion_test6.i'
+      exodiff = 'block_deletion_test6_out.e'
+
+      detail = "a 3D non-concave subdomain;"
+    []
+    [block_deletion_test7]
+      type = 'Exodiff'
+      input = 'block_deletion_test7.i'
+      exodiff = 'block_deletion_test7_out.e'
+
+      detail = "a 2D removal of a union of disjoint pieces;"
+    []
+    [block_deletion_test8]
+      type = 'Exodiff'
+      input = 'block_deletion_test8.i'
+      exodiff = 'block_deletion_test8_out.e'
+
+      detail = "a 2D removal of a subdomain containing a nodeset;"
+    []
+    [block_deletion_test9]
+      type = 'Exodiff'
+      input = 'block_deletion_test9.i'
+      exodiff = 'block_deletion_test9_out.e'
+
+      detail = "a 2D removal of a subdomain that eliminates sideset;"
+    []
+    [block_deletion_test10]
+      type = 'Exodiff'
+      input = 'block_deletion_test10.i'
+      exodiff = 'block_deletion_test10_out.e'
+
+      detail = "a 2D removal of a subdomain containing a sideset;"
+    []
+    [block_deletion_test12]
+      type = 'Exodiff'
+      input = 'block_deletion_test12.i'
+      exodiff = 'block_deletion_test12_out.e'
+
+      detail = "a 2D concave subdomain with a cut across elements."
+    []
+  []
 []

test/tests/meshgenerators/image_mesh_generator/tests

@@ -1,5 +1,5 @@
 [Tests]
-  [./image_mesh_generator_test]
+  [image_mesh_generator_test]
     type = 'Exodiff'
     input = 'image_mesh_generator.i'
     cli_args = '--mesh-only'
@@ -9,5 +9,31 @@
     issues = '#11640'
     mesh_mode = 'REPLICATED'
     recover = false
-  [../]
+  []
+
+  [image]
+    requirement = "The system shall support creating subdomains from"
+    issues = '#13814'
+    design = Mesh/index.md
+
+    [2d]
+      # Test ability to read in a single 20x20 image and assign subdomain ids based on image
+      type = Exodiff
+      input = image_2d.i
+      exodiff = image_2d_out.e
+      vtk = true
+      method = '!DBG' # This test is slow in debug b/c of calls to libMesh::MeshTools::libmesh_assert_valid_dof_ids
+
+      detail = "2D and"
+    []
+    [3d]
+      # Test ability to read in a single 20x20x20 stack of images and assign subdomain ids based on image
+      type = Exodiff
+      input = image_3d.i
+      exodiff = image_3d_out.e
+      vtk = true
+
+      detail = "3D images."
+    []
+  []
 []

test/tests/meshgenerators/lower_d_block_generator/tests

@@ -20,4 +20,29 @@
       recover = false
     [../]
   [../]
+
+  [lower]
+    requirement = "The system shall support the creation of lower dimensional elements on an "
+                  "existing sideset for"
+    issues = '#13814'
+    design = Mesh/index.md
+
+    [first_order]
+      type = Exodiff
+      exodiff = 'lower_d_out.e'
+      input = 'lower_d.i'
+      mesh_mode = REPLICATED
+
+      detail = "first-order and"
+    []
+    [second_order]
+      type = Exodiff
+      exodiff = 'lower_d_second_order_out.e'
+      input = 'lower_d.i'
+      mesh_mode = REPLICATED
+      cli_args = 'Mesh/second_order=true Outputs/file_base=lower_d_second_order_out '
+                 'GlobalParams/order=SECOND Mesh/gen/nx=5 Mesh/gen/ny=5'
+
+      detail = "second-order elements."
+    []
 []

test/tests/meshgenerators/mesh_extruder_generator/tests

@@ -15,6 +15,14 @@
       detail = 'from 2D quads to 3D hexes,'
     []
 
+    [tri_test]
+      type = 'Exodiff'
+      input = 'extruder_tri.i'
+      exodiff = 'out_tri.e'
+
+      detail = "2D triangular elements;"
+    []
+
     [new_subdomains]
       type = 'Exodiff'
       input = 'extrude_remap_layer1.i'

test/tests/meshgenerators/subdomain_id_generator/tests

@@ -9,6 +9,6 @@
 
     requirement = 'The system shall have the ability to change or overwrite the subdomain IDs of all elements in a mesh.'
     design = 'meshgenerators/SubdomainIDGenerator.md'
-    issues = '#11640'
+    issues = '#11640 #13814'
   [../]
 []