Add test for function loading data from JSON

refs idaholab#25058

test/tests/functions/piecewise_constant/gold/piecewise_constant_json_out.csv

@@ -0,0 +1,12 @@
+time,from_json
+0,1
+1,1
+2,1
+3,1
+4,1
+5,1
+6,-1
+7,-1
+8,10
+9,10
+10,10

test/tests/functions/piecewise_constant/piecewise_constant.i

@@ -1,8 +1,8 @@
 # This tests the PiecewiseConstant function.
 # There are four variables and four functions: a,b,c, and d.  The diffusion equation is "solved"
-# for each of these variables with a boundary condition of type FunctionDirchletBC applied to a boundary
+# for each of these variables with a boundary condition of type FunctionDirichletBC applied to a boundary
 # (i.e. node set) that includes every node in the element, so the solution is the boundary condition defined by the function.
-#  Each boundary condition uses a function of type PiecewiseConstant.
+# Each boundary condition uses a function of type PiecewiseConstant.
 #
 # The value of the variables should correspond to the function.
 
@@ -16,100 +16,100 @@
 
 [Variables]
 
-  [./aVar]
+  [aVar]
     order = FIRST
     family = LAGRANGE
     initial_condition = 0.1
-  [../]
-  [./bVar]
+  []
+  [bVar]
     order = FIRST
     family = LAGRANGE
     initial_condition = 0.1
-  [../]
-  [./cVar]
+  []
+  [cVar]
     order = FIRST
     family = LAGRANGE
     initial_condition = 0.1
-  [../]
-  [./dVar]
+  []
+  [dVar]
     order = FIRST
     family = LAGRANGE
     initial_condition = 0.1
-  [../]
+  []
 []
 
 [Functions]
-  [./a]
+  [a]
     type = PiecewiseConstant
     xy_data = '0.5 0.1
                1.0 0.2
                1.5 0.1'
     direction = left
-  [../]
-  [./b]
+  []
+  [b]
     type = PiecewiseConstant
     x = '0.5 1.0 1.5'
     y = '0.1 0.2 0.1'
     direction = right
-  [../]
-  [./c]
+  []
+  [c]
     type = PiecewiseConstant
     data_file = pc.csv
     direction = left
     format = columns
-  [../]
-  [./d]
+  []
+  [d]
     type = PiecewiseConstant
     data_file = pc.csv
     direction = right
     format = columns
-  [../]
+  []
 []
 
 [Kernels]
-  [./diffa]
+  [diffa]
     type = Diffusion
     variable = aVar
-  [../]
-  [./diffb]
+  []
+  [diffb]
     type = Diffusion
     variable = bVar
-  [../]
-  [./diffc]
+  []
+  [diffc]
     type = Diffusion
     variable = cVar
-  [../]
-  [./diffd]
+  []
+  [diffd]
     type = Diffusion
     variable = dVar
-  [../]
+  []
 []
 
 [BCs]
-  [./a]
+  [a]
     type = FunctionDirichletBC
     variable = aVar
     boundary = '1'
     function = a
-  [../]
-  [./b]
+  []
+  [b]
     type = FunctionDirichletBC
     variable = bVar
     boundary = '1'
     function = b
-  [../]
-  [./c]
+  []
+  [c]
     type = FunctionDirichletBC
     variable = cVar
     boundary = '1'
     function = c
-  [../]
-  [./d]
+  []
+  [d]
     type = FunctionDirichletBC
     variable = dVar
     boundary = '1'
     function = d
-  [../]
+  []
 []
 
 [Executioner]

test/tests/functions/piecewise_constant/piecewise_constant_json.i

@@ -0,0 +1,43 @@
+[Mesh]
+  type = GeneratedMesh
+  dim = 1
+[]
+
+[Problem]
+  solve = false
+[]
+
+[UserObjects]
+  [json]
+    type = JSONFileReader
+    filename = 'function_values.json'
+  []
+[]
+
+[Functions]
+  [from_json]
+    type = PiecewiseConstant
+    json_uo = 'json'
+    x_keys = "los_datos some_key some_other_key"
+    y_keys = "los_datos second_key some_other_key"
+  []
+[]
+
+[Postprocessors]
+  [from_json]
+    type = FunctionValuePostprocessor
+    function = from_json
+    execute_on = 'TIMESTEP_END INITIAL'
+  []
+[]
+
+[Executioner]
+  type = Transient
+  dt = 1
+  start_time = 0
+  end_time = 10
+[]
+
+[Outputs]
+  csv = true
+[]

test/tests/functions/piecewise_constant/piecewise_constant_simple.i

@@ -8,7 +8,7 @@
 []
 
 [Functions]
-  [./left]
+  [left]
     type = PiecewiseConstant
     xy_data = '-8   4
                -7   3
@@ -20,28 +20,28 @@
                8    4'
     direction = left
     scale_factor = 2
-  [../]
-  [./right]
+  []
+  [right]
     type = PiecewiseConstant
     x = '-8 -7 -5.5 -2 2 5.5 7 8'
     y = ' 4  3  2    1 1 2   3 4'
     direction = right
     scale_factor = 2
-  [../]
-  [./left_inclusive]
+  []
+  [left_inclusive]
     type = PiecewiseConstant
     x = '-8 -7 -5.5 -2 2 5.5 7 8'
     y = ' 4  3  2    1 1 2   3 4'
     direction = left_inclusive
     scale_factor = 2
-  [../]
-  [./right_inclusive]
+  []
+  [right_inclusive]
     type = PiecewiseConstant
     x = '-8 -7 -5.5 -2 2 5.5 7 8'
     y = ' 4  3  2    1 1 2   3 4'
     direction = right_inclusive
     scale_factor = 2
-  [../]
+  []
 []
 
 [Postprocessors]

test/tests/functions/piecewise_constant/tests

@@ -1,16 +1,28 @@
 [Tests]
-  issues = '#2272'
+  issues = '#2272 #xxx'
   design = 'source/functions/PiecewiseConstant.md'
-  [./piecewise_constant]
+  [piecewise_constant]
     type = 'Exodiff'
     input = 'piecewise_constant.i'
     exodiff = 'piecewise_constant_out.e'
-    requirement = "The Function system shall include an object that creates a function based on x- and y-data pairs and returns an explicit value from the supplied data when queried (i.e., linear interpolation is not performed)."
-  [../]
-  [./piecewise_constant_simple]
+    requirement = "The system shall include an object that creates a function based on x- and y-data "
+                  "pairs and returns an explicit value from the supplied data when queried (i.e., "
+                  "linear interpolation is not performed)."
+  []
+  [piecewise_constant_simple]
     type = 'CSVDiff'
     input = 'piecewise_constant_simple.i'
     csvdiff = 'piecewise_constant_simple_out.csv'
-    requirement = "The Function system shall include an object that creates a function based on x- and y-data pairs and returns an explicit value from the supplied data when queried (i.e., linear interpolation is not performed) in a simple simulation, with both negative and positive values."
-  [../]
+    requirement = "The system shall include an object that creates a function based on x- and y-data "
+                  "pairs and returns an explicit value from the supplied data when queried (i.e., "
+                  "linear interpolation is not performed) in a simple simulation, with both negative "
+                  "and positive values."
+  []
+  [piecewise_constant_from_json]
+    type = CSVDiff
+    input = 'piecewise_constant_json.i'
+    csvdiff = 'piecewise_constant_json_out.csv'
+    requirement = "The system shall be able to compute a piecewise constant function based on x- and "
+                  "y-data loaded from a JSON file."
+  []
 []