diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9c81a057131..6a8241e46c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -791,12 +791,13 @@ endif()
 
 # Tests #######################################################################
 #
+if(BUILD_TESTING)
+    enable_testing()
 
-#if(BUILD_TESTING)
-#    enable_testing()
-#
-#    add_test(...)
-#endif()
+    if(WarpX_APP)
+        add_subdirectory(Examples)
+    endif()
+endif()
 
 
 # Status Summary for Build Options ############################################
diff --git a/Examples/CMakeLists.txt b/Examples/CMakeLists.txt
new file mode 100644
index 00000000000..3d49bb052a5
--- /dev/null
+++ b/Examples/CMakeLists.txt
@@ -0,0 +1,175 @@
+# Configuration ###############################################################
+#
+if(WarpX_MPI)
+    # OpenMPI root guard: https://github.com/open-mpi/ompi/issues/4451
+    if("$ENV{USER}" STREQUAL "root")
+        # calling even --help as root will abort and warn on stderr
+        execute_process(
+            COMMAND ${MPIEXEC_EXECUTABLE} --help
+            ERROR_VARIABLE MPIEXEC_HELP_TEXT
+            OUTPUT_STRIP_TRAILING_WHITESPACE
+        )
+        if(${MPIEXEC_HELP_TEXT} MATCHES "^.*allow-run-as-root.*$")
+            set(MPI_ALLOW_ROOT --allow-run-as-root)
+        endif()
+    endif()
+    set(MPI_TEST_EXE
+        ${MPIEXEC_EXECUTABLE}
+        ${MPI_ALLOW_ROOT}
+        ${MPIEXEC_NUMPROC_FLAG} 2
+        ${MPIEXEC_POSTFLAGS}
+        ${MPIEXEC_PREFLAGS}
+    )
+endif()
+
+# Add a WarpX test set (with sub-tests)
+#
+function(add_warpx_test
+    name
+    mpi
+    dims
+    inputs_base
+    inputs_test
+    analysis
+    output
+)
+    # cannot run MPI tests w/o MPI support
+    if(mpi AND NOT WarpX_MPI)
+        return()
+    endif()
+
+    # make a unique run directory
+    file(MAKE_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${name})
+    set(THIS_WORKING_DIR ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${name})
+
+    set(THIS_MPI_TEST_EXE)
+    if(mpi)
+        set(THIS_MPI_TEST_EXE ${MPI_TEST_EXE})
+    endif()
+
+    # test run
+    add_test(
+        NAME ${name}.run
+        COMMAND
+            ${THIS_MPI_TEST_EXE}
+            $<TARGET_FILE:app_${dims}d>
+            ${WarpX_SOURCE_DIR}/${inputs_base}
+            amrex.abort_on_unused_inputs = 1
+            amrex.fpe_trap_invalid = 1
+            amrex.fpe_trap_overflow = 1
+            amrex.fpe_trap_zero = 1
+            amrex.throw_exception = 1
+            warpx.always_warn_immediately = 1
+            warpx.abort_on_warning_threshold = low
+            warpx.do_dynamic_scheduling = 0
+            warpx.serialize_initial_conditions = 1
+            # FILE parameter must be at the end,
+            # to possibly overwrite previous inputs
+            FILE = ${WarpX_SOURCE_DIR}/${inputs_test}
+        WORKING_DIRECTORY ${THIS_WORKING_DIR}
+    )
+
+    if(mpi)
+        set_property(TEST ${name}.run APPEND PROPERTY ENVIRONMENT "OMP_NUM_THREADS=1")
+    endif()
+
+    # test analysis
+    if(analysis)
+        add_test(
+            NAME ${name}.analysis
+            COMMAND
+                ${WarpX_SOURCE_DIR}/${analysis}
+                ${output}
+            WORKING_DIRECTORY ${THIS_WORKING_DIR}
+        )
+        set_property(TEST ${name}.analysis APPEND PROPERTY DEPENDS "${name}.run")
+    endif()
+
+endfunction()
+
+# Add tests (alphabetical order) ##############################################
+#
+
+# Langmuir_multi_2d_MR ########################################################
+#
+if(2 IN_LIST WarpX_DIMS)
+    add_warpx_test(
+        Langmuir_multi_2d_MR
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
+
+# Langmuir_multi_2d_MR_anisotropic ############################################
+#
+if(2 IN_LIST WarpX_DIMS)
+    add_warpx_test(
+        Langmuir_multi_2d_MR_anisotropic
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_anisotropic
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
+
+# Langmuir_multi_2d_MR_momentum_conserving ####################################
+#
+if(2 IN_LIST WarpX_DIMS)
+    add_warpx_test(
+        Langmuir_multi_2d_MR_momentum_conserving
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_momentum_conserving
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
+
+# Langmuir_multi_2d_MR_psatd ##################################################
+#
+if(2 IN_LIST WarpX_DIMS AND WarpX_FFT)
+    add_warpx_test(
+        Langmuir_multi_2d_MR_psatd
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_psatd
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
+
+# Langmuir_multi_2d_nodal #####################################################
+#
+if(2 IN_LIST WarpX_DIMS)
+    add_warpx_test(
+        Langmuir_multi_2d_nodal
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_nodal
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
+
+# Langmuir_multi_2d_psatd #####################################################
+#
+if(2 IN_LIST WarpX_DIMS AND WarpX_FFT)
+    add_warpx_test(
+        Langmuir_multi_2d_psatd
+        ON
+        2
+        Examples/Tests/langmuir/inputs_2d_base
+        Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_psatd
+        Examples/Tests/langmuir/analysis_2d.py
+        diags/diag1000080
+    )
+endif()
diff --git a/Examples/Tests/langmuir/inputs_2d b/Examples/Tests/langmuir/inputs_2d_base
similarity index 100%
rename from Examples/Tests/langmuir/inputs_2d
rename to Examples/Tests/langmuir/inputs_2d_base
diff --git a/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR
new file mode 100644
index 00000000000..586624654c1
--- /dev/null
+++ b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR
@@ -0,0 +1,9 @@
+# additional runtime parameters
+algo.maxwell_solver = ckc
+amr.max_level = 1
+amr.ref_ratio = 4
+diag1.electrons.variables = x z w ux uy uz
+diag1.positrons.variables = x z w ux uy uz
+warpx.fine_tag_hi =  10.e-6  10.e-6
+warpx.fine_tag_lo = -10.e-6 -10.e-6
+warpx.use_filter = 1
diff --git a/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_anisotropic b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_anisotropic
new file mode 100644
index 00000000000..91c2d1c80d3
--- /dev/null
+++ b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_MR_anisotropic
@@ -0,0 +1,9 @@
+# additional runtime parameters
+algo.maxwell_solver = ckc
+amr.max_level = 1
+amr.ref_ratio_vect = 4 2
+diag1.electrons.variables = x z w ux uy uz
+diag1.positrons.variables = x z w ux uy uz
+warpx.fine_tag_hi =  10.e-6  10.e-6
+warpx.fine_tag_lo = -10.e-6 -10.e-6
+warpx.use_filter = 1
diff --git a/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_nodal b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_nodal
new file mode 100644
index 00000000000..a5c132eef91
--- /dev/null
+++ b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_nodal
@@ -0,0 +1,5 @@
+# additional runtime parameters
+algo.current_deposition = direct
+diag1.electrons.variables = x z w ux uy uz
+diag1.positrons.variables = x z w ux uy uz
+warpx.grid_type = collocated
diff --git a/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_psatd b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_psatd
new file mode 100644
index 00000000000..343cc0cede1
--- /dev/null
+++ b/Examples/Tests/langmuir/inputs_2d_test_Langmuir_multi_2d_psatd
@@ -0,0 +1,8 @@
+# additional runtime parameters
+algo.maxwell_solver = psatd
+diag1.electrons.variables = x z w ux uy uz
+diag1.positrons.variables = x z w ux uy uz
+diag1.fields_to_plot = Ex Ey Ez jx jy jz part_per_cell
+psatd.current_correction = 0
+warpx.abort_on_warning_threshold = medium
+warpx.cfl = 0.7071067811865475
diff --git a/Regression/WarpX-tests.ini b/Regression/WarpX-tests.ini
index 17ecfd64f29..2ea8018fd8c 100644
--- a/Regression/WarpX-tests.ini
+++ b/Regression/WarpX-tests.ini
@@ -1011,7 +1011,7 @@ analysisOutputImage = langmuir_multi_1d_analysis.png
 
 [Langmuir_multi_2d_MR]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver = ckc  warpx.use_filter = 1  amr.max_level = 1  amr.ref_ratio = 4  warpx.fine_tag_lo = -10.e-6 -10.e-6  warpx.fine_tag_hi = 10.e-6 10.e-6  diag1.electrons.variables = x z w ux uy uz  diag1.positrons.variables = x z w ux uy uz
 dim = 2
 addToCompileString =
@@ -1026,7 +1026,7 @@ analysisOutputImage = Langmuir_multi_2d_MR.png
 
 [Langmuir_multi_2d_MR_anisotropic]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver = ckc  warpx.use_filter = 1  amr.max_level = 1 amr.ref_ratio_vect = 4 2 warpx.fine_tag_lo = -10.e-6 -10.e-6  warpx.fine_tag_hi = 10.e-6 10.e-6  diag1.electrons.variables = x z w ux uy uz  diag1.positrons.variables = x z w ux uy uz
 dim = 2
 addToCompileString =
@@ -1041,7 +1041,7 @@ analysisOutputImage = Langmuir_multi_2d_MR.png
 
 [Langmuir_multi_2d_MR_momentum_conserving]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=ckc warpx.use_filter=1 amr.max_level=1 amr.ref_ratio=4 warpx.fine_tag_lo=-10.e-6 -10.e-6 warpx.fine_tag_hi=10.e-6 10.e-6 algo.field_gathering=momentum-conserving diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz
 dim = 2
 addToCompileString =
@@ -1056,7 +1056,7 @@ analysisOutputImage = Langmuir_multi_2d_MR_momentum_conserving.png
 
 [Langmuir_multi_2d_MR_psatd]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver = psatd  warpx.use_filter = 1  amr.max_level = 1  amr.ref_ratio = 4  warpx.fine_tag_lo = -10.e-6 -10.e-6  warpx.fine_tag_hi = 10.e-6 10.e-6  diag1.electrons.variables = x z w ux uy uz  diag1.positrons.variables = x z w ux uy uz psatd.current_correction=0 warpx.abort_on_warning_threshold=medium
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1071,7 +1071,7 @@ analysisOutputImage = Langmuir_multi_2d_MR_psatd.png
 
 [Langmuir_multi_2d_nodal]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = warpx.grid_type=collocated algo.current_deposition=direct diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz
 dim = 2
 addToCompileString =
@@ -1086,7 +1086,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot=Ex Ey Ez jx jy jz part_per_cell warpx.cfl = 0.7071067811865475 psatd.current_correction=0 warpx.abort_on_warning_threshold=medium
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1101,7 +1101,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_current_correction]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd amr.max_grid_size=128 algo.current_deposition=esirkepov psatd.periodic_single_box_fft=1 psatd.current_correction=1 diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot =Ex Ey Ez jx jy jz part_per_cell rho divE warpx.cfl = 0.7071067811865475
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1116,7 +1116,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_current_correction_nodal]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd amr.max_grid_size=128 algo.current_deposition=direct psatd.periodic_single_box_fft=1 psatd.current_correction=1 warpx.grid_type=collocated diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot =Ex Ey Ez jx jy jz part_per_cell rho divE warpx.cfl = 0.7071067811865475
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1131,7 +1131,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_momentum_conserving]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd algo.field_gathering=momentum-conserving diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot=Ex Ey Ez jx jy jz part_per_cell warpx.cfl = 0.7071067811865475 psatd.current_correction=0 warpx.abort_on_warning_threshold=medium
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1146,7 +1146,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_multiJ]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd warpx.cfl=0.7071067811865475 psatd.update_with_rho=1 warpx.do_multi_J=1 warpx.do_multi_J_n_depositions=2 psatd.solution_type=first-order psatd.J_in_time=linear warpx.abort_on_warning_threshold=medium
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1161,7 +1161,7 @@ analysisOutputImage = Langmuir_multi_2d_psatd_multiJ.png
 
 [Langmuir_multi_2d_psatd_multiJ_nodal]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd warpx.cfl=0.7071067811865475 psatd.update_with_rho=1 warpx.do_multi_J=1 warpx.do_multi_J_n_depositions=2 psatd.solution_type=first-order psatd.J_in_time=linear warpx.abort_on_warning_threshold=medium warpx.grid_type=collocated
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1176,7 +1176,7 @@ analysisOutputImage = Langmuir_multi_2d_psatd_multiJ_nodal.png
 
 [Langmuir_multi_2d_psatd_nodal]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd warpx.grid_type=collocated algo.current_deposition=direct diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot=Ex Ey Ez jx jy jz part_per_cell warpx.cfl = 0.7071067811865475 psatd.current_correction=0 warpx.abort_on_warning_threshold=medium
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1191,7 +1191,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_Vay_deposition]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd amr.max_grid_size=128 algo.current_deposition=vay diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot = Ex Ey Ez jx jy jz part_per_cell rho divE warpx.cfl = 0.7071067811865475
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1206,7 +1206,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_Vay_deposition_particle_shape_4]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd amr.max_grid_size=128 algo.current_deposition=vay diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot = Ex Ey Ez jx jy jz part_per_cell rho divE warpx.cfl = 0.7071067811865475 algo.particle_shape=4
 dim = 2
 addToCompileString = USE_FFT=TRUE
@@ -1221,7 +1221,7 @@ analysisOutputImage = langmuir_multi_2d_analysis.png
 
 [Langmuir_multi_2d_psatd_Vay_deposition_nodal]
 buildDir = .
-inputFile = Examples/Tests/langmuir/inputs_2d
+inputFile = Examples/Tests/langmuir/inputs_2d_base
 runtime_params = algo.maxwell_solver=psatd amr.max_grid_size=128 warpx.grid_type=collocated algo.current_deposition=vay diag1.electrons.variables=x z w ux uy uz diag1.positrons.variables=x z w ux uy uz diag1.fields_to_plot = Ex Ey Ez jx jy jz part_per_cell rho divE warpx.cfl = 0.7071067811865475
 dim = 2
 addToCompileString = USE_FFT=TRUE