libsvm instances during the unit tests are influenced by other coexisting instances and cause test failures

[JasonShin]

Context:
While trying to cover tests for WASM loaded SVM's predict, I've encountered an issue of incorrect prediction results between running a test by itself vs running tests in-band.

Problematic test:

it('should predict bodyfat scale dataset using C_SVC and LINEAR', () => {
      const rawData = fs.readFileSync(path.join(__dirname, '../samples/bodyfat_scale.txt'), 'utf-8');
      const data = rawData.split('\n').map((line) => line.split(' ').filter((el) => el));
      const labels = data.map((line) => +line.splice(0, 1)[0]);
      const features = data.map((line) => line.map((el) => +el.split(':')[1]));

      const svm = new SVM({
        type: SVMTypes.C_SVC,
        kernel: KernelTypes.LINEAR,
        epsilon: 0.001,
        quiet: true,
        probabilityEstimates: true,
      });
      return svm.loadWASM().then((loadedSVM) => {
        loadedSVM.train({ samples: features, labels });
        const predResult = loadedSVM.predict({
          samples: [features[0], features[1]],
        });
        loadedSVM.free();
        // TODO: It seems like other tests are influencing the result of this.
        // I don't know why so far, we should figure it out
        expect(predResult).toEqual([1, 1]);
      });
    });

When you run this test on its own, it passes without an issue since the loadedSVM instance is isolated. However, if you run this test in parallel/sequentially along with other tests, the prediction starts to return different values.

We should investigate why this is happening and devise a solution.

[JasonShin]

The issue occurs in both WASM and ASM.

[leo-p-labs]

I'm having a bug that comes from libsvm-ts/out/asm/libsvm.js even if there is no SVM instance loaded. I'm just calling accuracy_score(). I post it here since I think it's related to the same problem. If not I'll open a new issue.