test(lcms): disperse PR #232 review tests (B1–B7) into per-subject suites

The B1–B7 review regression tests lived in one PR-named file
(pr232_review_blocking.test.tsx). Move each into the test file that owns the
code it guards, matching the repo's subject-based test layout:

- B1 peak-add on a non-LCMS layout      -> sagas/saga_ui_lcms.test.tsx
- B2 getArea on cumulative-k data       -> helpers/integration.test.tsx
- B3 getAbsoluteArea from raw y          -> helpers/integration.test.tsx
- B4 Convert2Peak honours stored peaks   -> helpers/chem.test.tsx
- B7 convertThresEndPts precondition     -> helpers/chem.test.tsx
- B5 CV current-density chart factor     -> components/d3_multi/multi_focus.test.js (new)
- B7 drawBar empty-endpoint guard        -> components/d3_line_rect.test.js

B6 (UV-Vis update-path guard) is dropped: its test only re-implemented the
source inline (ViewerLineRect is not exported), so it guarded nothing in the
real component. Tracked as a follow-up needing a testable seam.

B5's submit/export factor (computeCvYScaleFactor) is already covered in
components/cmd_bar/r05_submit_btn.test.js, so it is not duplicated here.

No behaviour change — tests only. All moved assertions stay green.

refs #232

Author: PiTrem

src/__tests__/units/components/d3_line_rect.test.js

@@ -1,5 +1,6 @@
 import { isLcmsMsPageLoading } from '../../../components/d3_line_rect/index';
 import { pickTicIndex } from '../../../components/d3_line_rect/multi_focus';
+import RectFocus from '../../../components/d3_line_rect/rect_focus';
 
 describe('isLcmsMsPageLoading', () => {
   const buildMzEntity = (polarity, pageValues) => ({
@@ -66,3 +67,19 @@ describe('isLcmsMsPageLoading', () => {
     expect(isLcmsMsPageLoading([], state)).toEqual(true);
   });
 });
+
+// Review finding B7 (#232): drawBar reads tTrEndPts[0].y. Clearing the
+// threshold makes convertThresEndPts return [] (see chem.test.tsx) while the
+// MS bars are still present, so drawBar must guard the empty endpoint list
+// instead of crashing.
+describe('RectFocus.drawBar with an empty threshold-endpoint list (B7)', () => {
+  it('does not crash when tTrEndPts is empty but bars exist', () => {
+    const rf = Object.create(RectFocus.prototype);
+    rf.bars = {}; // truthy → passes the `if (!this.bars)` guard
+    rf.scales = { x: (v) => v, y: (v) => v }; // TfRescale reads focus.scales.{x,y}
+    rf.updatePathCall = () => {}; // stub out the d3 path update
+    rf.data = [{ x: 1, y: 2 }]; // bars present
+    rf.tTrEndPts = []; // cleared threshold → empty endpoints
+    expect(() => rf.drawBar()).not.toThrow();
+  });
+});

src/__tests__/units/components/d3_multi/multi_focus.test.js

@@ -0,0 +1,30 @@
+import MultiFocus from '../../../../components/d3_multi/multi_focus';
+import { LIST_LAYOUT } from '../../../../constants/list_layout';
+
+// Review finding B5 (#232): the CV current-density factor on the chart
+// (computeYTransformFactor) must convert the electrode area to cm² exactly
+// once. Physically 100 mm² == 1 cm², so the factor for the two must match —
+// double-dividing by 100 for mm² made it 100x too small.
+// (computeYTransformFactor is pure — it ignores `this` — so it is called via
+//  the prototype.)
+describe('MultiFocus.computeYTransformFactor — CV current density (B5)', () => {
+  const compute = (cvSt) => MultiFocus.prototype.computeYTransformFactor.call(
+    {}, LIST_LAYOUT.CYCLIC_VOLTAMMETRY, cvSt, { yUnit: 'A' },
+  );
+
+  it('treats 100 mm² the same as 1 cm²', () => {
+    const fMm2 = compute({ useCurrentDensity: true, areaValue: 100, areaUnit: 'mm²' });
+    const fCm2 = compute({ useCurrentDensity: true, areaValue: 1, areaUnit: 'cm²' });
+    expect(fMm2).toBeCloseTo(fCm2);
+    expect(fMm2).toBeCloseTo(1.0); // double /100 for mm² gives 0.01
+  });
+
+  it('gives A/cm² for a mm² area (factor = 100 / area_mm²)', () => {
+    // 50 mm² == 0.5 cm² → factor 1 / 0.5 = 2
+    expect(compute({ useCurrentDensity: true, areaValue: 50, areaUnit: 'mm²' })).toBeCloseTo(2.0);
+  });
+
+  it('returns 1.0 when current density is off', () => {
+    expect(compute({ useCurrentDensity: false })).toBeCloseTo(1.0);
+  });
+});

src/__tests__/units/helpers/chem.test.tsx

@@ -3,6 +3,7 @@ import {
   ToFrequency, Convert2Scan, Convert2Thres, GetComparisons, Convert2DValue,
   GetCyclicVoltaRatio, GetCyclicVoltaPeakSeparate, convertTopic,
   Convert2MaxMinPeak, Feature2MaxMinPeak, GetCyclicVoltaShiftOffset, GetCyclicVoltaPreviousShift,
+  convertThresEndPts,
 } from "../../../helpers/chem";
 import nmr1HJcamp from "../../fixtures/nmr1h_jcamp";
 import aifJcamp1 from "../../fixtures/aif_jcamp_1";
@@ -193,6 +194,29 @@ describe('Test for chem helper', () => {
       const peaks = Convert2Peak(feature, threshold, offset)
       expect(peaks).toEqual([{x: 2, y: 2}, {x: -2, y: -2}])
     })
+
+    // Review finding B4 (#232): for an LC/MS feature carrying edited/stored
+    // peaks, Convert2Peak must return those peaks with the offset applied,
+    // rather than recomputing them from the raw data and dropping the offset.
+    it('honours stored LC/MS peaks and applies the offset', () => {
+      const feature = {
+        operation: { layout: 'LC/MS' },
+        data: [{ x: [10, 11, 12], y: [1, 5, 1] }],
+        peaks: [{ x: 5, y: 100 }], // user-edited / stored peaks
+      }
+      const peaks = Convert2Peak(feature, 0, 2)
+      expect(peaks).toEqual([{ x: 3, y: 100 }])
+    })
+  })
+
+  // Review finding B7 (#232) precondition: clearing the threshold input yields
+  // an empty endpoint list (this is the state that made drawBar crash — see
+  // d3_line_rect.test.js for the drawBar guard itself).
+  describe('convertThresEndPts', () => {
+    it('returns [] when the threshold is cleared', () => {
+      const feature = { maxY: 100, maxX: 10, minX: 0, data: [{ x: [1, 2], y: [3, 4] }] }
+      expect(convertThresEndPts(feature, '')).toEqual([])
+    })
   })
 
   describe('Feature2Peak', () => {

src/__tests__/units/helpers/integration.test.tsx

@@ -42,4 +42,40 @@ describe('Test helper for integration', () => {
       expect(area).toEqual('0.52')
     })
   })
+
+  // Review finding B2 (#232): NMR/CV integration data carries a cumulative
+  // running integral `k` (from calcXYK). The integral over [xL,xU] is the
+  // difference k(xU)-k(xL); getArea must NOT trapezoidally integrate `k` again.
+  describe('getArea on cumulative-k (NMR/CV) data — review B2', () => {
+    // x ramp, constant normalised signal => k increases by 1 each sample.
+    const data = [
+      { x: 0, y: 1, k: 0 },
+      { x: 1, y: 1, k: 1 },
+      { x: 2, y: 1, k: 2 },
+      { x: 3, y: 1, k: 3 },
+    ]
+
+    it('equals the cumulative difference k(xU)-k(xL)', () => {
+      expect(getArea(0, 3, data)).toBeCloseTo(3) // double-integrating k gives 4.5
+    })
+
+    it('is invariant to a constant baseline offset of the cumulative curve', () => {
+      const shifted = data.map((p) => ({ ...p, k: p.k + 100 }))
+      // The signal integral cannot depend on the integration constant of k.
+      expect(getArea(0, 3, shifted)).toBeCloseTo(getArea(0, 3, data))
+    })
+  })
+
+  // Review finding B3 (#232): getAbsoluteArea must use the raw signal `y`
+  // (baseline-subtracted), not the cumulative `k`, when data carries both.
+  describe('getAbsoluteArea on data carrying both y and k — review B3', () => {
+    const data = [
+      { x: 1, y: 1, k: 1 },
+      { x: 2, y: 2, k: 3 }, // peak in the raw signal y
+      { x: 3, y: 1, k: 4 },
+    ]
+    it('computes the area from raw y (1.0), not from cumulative k (0.5)', () => {
+      expect(getAbsoluteArea(0, 4, data)).toBeCloseTo(1.0)
+    })
+  })
 })

src/__tests__/units/pr232_review_blocking.test.tsx

@@ -258,6 +258,33 @@ describe('saga_ui — clickUiTarget LCMS branches', () => {
     expect(value).toBeUndefined();
   });
 
+  // Review finding B1 (#232): on a NON-LCMS layout, PEAK_ADD must still add a
+  // positive edit-peak (EDITPEAK.ADD_POSITIVE). The LCMS-only path must not
+  // swallow peak-add for NMR/IR/MS layouts.
+  it('PEAK_ADD on a non-LCMS layout dispatches EDITPEAK.ADD_POSITIVE', () => {
+    const action = {
+      type: UI.CLICK_TARGET,
+      payload: { x: 5, y: 10 },
+      sourceHint: null,
+      onPeak: false,
+      onPecker: false,
+      voltammetryPeakIdx: 0,
+    } as any;
+    const iter = clickUiTarget(action);
+
+    const { value } = drainSelects(iter, [
+      LIST_UI_SWEEP_TYPE.PEAK_ADD,
+      { curveIdx: 0 },
+      { uvvis: { selectedWaveLength: null, currentSpectrum: { peaks: [] } } },
+      LIST_LAYOUT.H1, // a normal NMR layout — not LC/MS
+    ]);
+
+    expect(value).toEqual(put({
+      type: EDITPEAK.ADD_POSITIVE,
+      payload: { dataToAdd: action.payload, curveIdx: 0 },
+    }));
+  });
+
   it('PEAK_DELETE on LCMS uses REMOVE_HPLCMS_PEAK for the selected wavelength', () => {
     const action = {
       type: UI.CLICK_TARGET,