test improvements: rewrite edit() and open() usage with testing mocks

Author: eszmw

InstructorResources/Solutions/FiniteDifferenceSoln.mlx

@@ -3,3 +3,9 @@
 KnownIssuesID = "";
 % ---- Pre-run commands -----
 
+edit = @(str)MyEdit(str);
+
+function MyEdit(str)
+assert(exist(str,"file"))
+disp("Edit the file " + str)
+end

InstructorResources/Solutions/ImplementExplicitSolverSoln.mlx

@@ -3,3 +3,9 @@
 KnownIssuesID = "";
 % ---- Pre-run commands -----
 
+edit = @(str)MyEdit(str);
+
+function MyEdit(str)
+assert(exist(str,"file"))
+disp("Edit the file " + str)
+end

InstructorResources/Solutions/MethodOfCharacteristicsSoln.mlx

@@ -3,3 +3,9 @@
 KnownIssuesID = "";
 % ---- Pre-run commands -----
 
+open = @(str)MyEdit(str);
+
+function MyEdit(str)
+assert(exist(str,"file"))
+disp("Edit the file " + str)
+end

Scripts/FiniteDifference.mlx

@@ -3,3 +3,9 @@
 KnownIssuesID = "";
 % ---- Pre-run commands -----
 
+open = @(str)MyEdit(str);
+
+function MyEdit(str)
+assert(exist(str,"file"))
+disp("Edit the file " + str)
+end

Scripts/ImplementExplicitSolver.mlx

@@ -3,3 +3,9 @@
 KnownIssuesID = "";
 % ---- Pre-run commands -----
 
+edit = @(str)MyEdit(str);
+
+function MyEdit(str)
+assert(exist(str,"file"))
+disp("Edit the file " + str)
+end