Add codecov to build.yml to upload coverage

.github/workflows/build.yml

@@ -87,3 +87,38 @@ jobs:
               uses: matlab-actions/run-tests@v2
               with:
                  select-by-folder: opentelemetry-matlab/test
+    codecov-ubuntu:
+        runs-on: ubuntu-latest
+        env:
+            OPENTELEMETRY_MATLAB_INSTALL: "${{ github.workspace }}/otel_matlab_install"
+            SYSTEM_LIBSTDCPP_PATH: "/usr/lib/x86_64-linux-gnu/libstdc++.so.6"
+        steps:
+            - name: Download OpenTelemetry-Matlab source
+              uses: actions/checkout@v3
+              with: 
+                path: opentelemetry-matlab
+            - name: Install MATLAB
+              uses: matlab-actions/setup-matlab@v2
+              with:
+                products: MATLAB_Compiler
+            - name: Build OpenTelemetry-Matlab
+              run: |
+                  cd opentelemetry-matlab
+                  cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DWITH_EXAMPLES=ON -DCMAKE_INSTALL_PREFIX=${{ env.OPENTELEMETRY_MATLAB_INSTALL }}
+                  cmake --build build --config Release --target install
+            - name: Codecov
+              env:
+                 # The version of libstdc++ that is bundled with MATLAB is used when building MEX files.
+                 # This version of libstdc++ is incompatible with the system version of libstdc++.
+                 # As a workaround, set LD_PRELOAD to use the system version of libstdc++ with MATLAB.
+                 LD_PRELOAD: ${{ env.SYSTEM_LIBSTDCPP_PATH }}
+
+                 # Add the installation directory to the MATLAB Search Path by
+                 # setting the MATLABPATH environment variable.
+                 MATLABPATH: ${{ env.OPENTELEMETRY_MATLAB_INSTALL }}
+              uses: matlab-actions/run-tests@v2
+              with:
+                 source-folder: install/+opentelemetry
+                 code-coverage-cobertura: cobertura.xml
+                 token: ${{ secrets.CODECOV_TOKEN }}
+                 slug: mathworks/OpenTelemetry-Matlab

testToolbox.m

@@ -0,0 +1,14 @@
+suite = testsuite(fullfile('test/'));
+runner = testrunner("textoutput");
+import matlab.unittest.plugins.CodeCoveragePlugin
+import matlab.unittest.plugins.codecoverage.CoverageReport
+import matlab.unittest.plugins.codecoverage.CoberturaFormat
+
+sourceFile = fullfile('install','+opentelemetry');
+reportFile = fullfile("cobertura.xml");
+reportFormat = CoberturaFormat(reportFile);
+p = CodeCoveragePlugin.forFolder(sourceFile,'IncludingSubfolders',true,'Producing',reportFormat);
+runner.addPlugin(p);
+result = runner.run(suite);
+
+result.assertSuccess()