Add comprehensive test suite for processFNIRS2

Introduces unit, integration, quick, and synthetic tests for pf2_base, including fixtures for sample data, full pipeline and roundtrip SNIRF tests, and quick validation scripts for import, export, and processing. Also adds synthetic artifact generation for testing, updates documentation, and removes obsolete readme file.

Author: AdrianCurtin

+pf2_base/+tests/+fixtures/SampleDataFixture.m

@@ -0,0 +1,112 @@
+classdef SampleDataFixture < matlab.unittest.fixtures.Fixture
+% SAMPLEDATAFIXTURE Test fixture providing pre-loaded fNIRS sample data
+%
+% Provides shared access to sample fNIRS datasets for unit and integration
+% tests. Loading sample data once per test class (via fixture) improves
+% test performance compared to loading in each test method.
+%
+% Reference:
+%   Internal pf2 test infrastructure. See matlab.unittest.fixtures.Fixture.
+%
+% Syntax:
+%   fixture = pf2_base.tests.fixtures.SampleDataFixture()
+%   testCase.applyFixture(fixture)
+%
+% Properties:
+%   fNIR2000   - fNIR 2000 sample data [struct]
+%                18-channel prefrontal probe, 10 Hz sampling rate.
+%                Loaded via pf2.import.sampleData.fNIR2000().
+%   fNIR1200   - fNIR 1200 sample data [struct]
+%                16-channel probe configuration.
+%                Loaded via pf2.import.sampleData.fNIR1200().
+%   hitachi3x5 - Hitachi ETG-4000 3x5 sample data [struct]
+%                22-channel probe (3x5 optode array).
+%                Loaded via pf2.import.sampleData.Hitachi_ETG4000_3x5().
+%
+% Example:
+%   classdef MyTest < matlab.unittest.TestCase
+%       methods (TestClassSetup)
+%           function setupFixture(testCase)
+%               fixture = pf2_base.tests.fixtures.SampleDataFixture();
+%               testCase.applyFixture(fixture);
+%               testCase.addTeardown(@() disp('Fixture cleanup'));
+%           end
+%       end
+%
+%       methods (Test)
+%           function testProcessing(testCase)
+%               fixture = testCase.getSharedTestFixtures(...
+%                   'pf2_base.tests.fixtures.SampleDataFixture');
+%               data = fixture.fNIR2000;
+%               result = processFNIRS2(data);
+%               testCase.verifyNotEmpty(result.HbO);
+%           end
+%       end
+%   end
+%
+% Notes:
+%   - Sample data files must exist in processFNIRS2/sampledata/
+%   - Fixture loads data silently (channelCheck=false, no GUI)
+%   - Data is loaded once and shared across all tests using the fixture
+%
+% See also: matlab.unittest.fixtures.Fixture, pf2.import.sampleData
+
+    properties (SetAccess = private)
+        % fNIR2000 - fNIR 2000 sample data struct
+        %   18-channel prefrontal probe, 10 Hz sampling rate.
+        %   Contains raw intensity data, markers, and device configuration.
+        fNIR2000
+
+        % fNIR1200 - fNIR 1200 sample data struct
+        %   16-channel probe configuration.
+        %   Contains raw intensity data, markers, and device configuration.
+        fNIR1200
+
+        % hitachi3x5 - Hitachi ETG-4000 3x5 sample data struct
+        %   22-channel probe from 3x5 optode array.
+        %   Contains raw intensity data and device configuration.
+        hitachi3x5
+    end
+
+    methods
+        function setup(fixture)
+            % SETUP Load all sample datasets
+            %
+            % Loads fNIR2000, fNIR1200, and Hitachi 3x5 sample data.
+            % Called automatically when fixture is applied to test case.
+
+            % Load fNIR 2000 sample data (18 channels, prefrontal)
+            fixture.fNIR2000 = pf2.import.sampleData.fNIR2000();
+
+            % Load fNIR 1200 sample data (16 channels)
+            fixture.fNIR1200 = pf2.import.sampleData.fNIR1200();
+
+            % Load Hitachi ETG-4000 3x5 sample data (22 channels)
+            fixture.hitachi3x5 = pf2.import.sampleData.Hitachi_ETG4000_3x5();
+        end
+
+        function teardown(~)
+            % TEARDOWN Clean up after fixture use
+            %
+            % No cleanup required - data is released when fixture is destroyed.
+        end
+    end
+
+    methods (Access = protected)
+        function tf = isCompatible(fixture, other)
+            % ISCOMPATIBLE Check if two fixtures are compatible
+            %
+            % Returns true if both fixtures are SampleDataFixture instances.
+            % Required by matlab.unittest.fixtures.Fixture interface.
+            %
+            % Inputs:
+            %   fixture - This fixture instance
+            %   other   - Another fixture to compare
+            %
+            % Outputs:
+            %   tf - True if fixtures are compatible (same class)
+
+            tf = isa(other, 'pf2_base.tests.fixtures.SampleDataFixture');
+        end
+    end
+end