feat: add calculator component testing and contributor guidelines

CODING.md

@@ -31,3 +31,17 @@ can even run your own!
 a specific bee client, written in the `go` programming language, while
 `bee`, in lower case, refers to any worker that can join a swarm
 (e.g. any client implementation that speaks the Swarm protocol).
+
+## Component Testing
+
+### Calculator Component
+
+If you modify `src/components/AmountAndDepthCalc.js` (the postage stamp cost calculator), you **must** run the automated tests before submitting your PR:
+
+```bash
+node src/components/AmountAndDepthCalc.test.js
+```
+
+All 37 tests must pass (`PASSED: 37`). If any test fails, your changes have introduced a bug. Fix the issue and re-run the tests.
+
+For detailed information about what the tests cover and how to debug failures, see `.claude/README-CALCULATOR-TESTING.md`.

README.md

@@ -50,6 +50,28 @@ npm run build
 
 This command generates static content into the `build` directory and can be served using any static contents hosting service.
 
+### Testing
+
+#### Calculator Component Tests
+
+If you modify the postage stamp cost calculator component (`src/components/AmountAndDepthCalc.js`), you should run the automated tests to verify your changes:
+
+```bash
+node src/components/AmountAndDepthCalc.test.js
+```
+
+This runs 37 unit tests covering:
+- Time conversion (hours, days, weeks, years)
+- Depth selection and cost calculation
+- Data table integrity and consistency
+- Edge cases and boundary conditions
+
+**Expected output:** `PASSED: 37` (all tests should pass)
+
+If any tests fail, it indicates a bug in the calculator logic. Please investigate and fix before submitting your PR.
+
+For more information about the calculator tests, see: `.claude/README-CALCULATOR-TESTING.md`
+
 
 ### Note about lunr search plugin
 

src/components/AmountAndDepthCalc.js

@@ -24,31 +24,31 @@ function FetchPriceComponent() {
   const depthToEffectiveVolume = {
     unencrypted: {
       none: {
-        17: { label: "44.70 kB", gb: 0.000043 },
-        18: { label: "6.66 MB", gb: 0.006504 },
-        19: { label: "112.06 MB", gb: 0.109434 },
-        20: { label: "687.62 MB", gb: 0.671504 },
-        21: { label: "2.60 GB", gb: 2.60 },
-        22: { label: "7.73 GB", gb: 7.73 },
-        23: { label: "19.94 GB", gb: 19.94 },
-        24: { label: "47.06 GB", gb: 47.06 },
-        25: { label: "105.51 GB", gb: 105.51 },
-        26: { label: "227.98 GB", gb: 227.98 },
-        27: { label: "476.68 GB", gb: 476.68 },
-        28: { label: "993.65 GB", gb: 993.65 },
-        29: { label: "2.04 TB", gb: 2088.96 },
-        30: { label: "4.17 TB", gb: 4270.08 },
-        31: { label: "8.45 TB", gb: 8652.80 },
-        32: { label: "17.07 TB", gb: 17479.68 },
-        33: { label: "34.36 TB", gb: 35184.64 },
-        34: { label: "69.04 TB", gb: 70696.96 },
-        35: { label: "138.54 TB", gb: 141864.96 },
-        36: { label: "277.72 TB", gb: 284385.28 },
-        37: { label: "556.35 TB", gb: 569702.40 },
-        38: { label: "1.11 PB", gb: 1163919.36 },
-        39: { label: "2.23 PB", gb: 2338324.48 },
-        40: { label: "4.46 PB", gb: 4676648.96 },
-        41: { label: "8.93 PB", gb: 9363783.68 },
+        17: { label: "39.932 KB", gb: 0.000039 },
+        18: { label: "5.808 MB", gb: 0.005664 },
+        19: { label: "97.742 MB", gb: 0.095432 },
+        20: { label: "599.775 MB", gb: 0.585527 },
+        21: { label: "2.217 GB", gb: 2.217 },
+        22: { label: "6.584 GB", gb: 6.584 },
+        23: { label: "16.987 GB", gb: 16.987 },
+        24: { label: "33.974 GB", gb: 33.974 },
+        25: { label: "67.948 GB", gb: 67.948 },
+        26: { label: "135.896 GB", gb: 135.896 },
+        27: { label: "271.792 GB", gb: 271.792 },
+        28: { label: "543.584 GB", gb: 543.584 },
+        29: { label: "1.087 TB", gb: 1087.168 },
+        30: { label: "2.174 TB", gb: 2174.336 },
+        31: { label: "4.349 TB", gb: 4348.672 },
+        32: { label: "8.698 TB", gb: 8697.344 },
+        33: { label: "17.395 TB", gb: 17394.688 },
+        34: { label: "34.791 TB", gb: 34789.376 },
+        35: { label: "69.582 TB", gb: 69578.752 },
+        36: { label: "139.163 TB", gb: 139157.504 },
+        37: { label: "278.327 TB", gb: 278315.008 },
+        38: { label: "556.654 TB", gb: 556630.016 },
+        39: { label: "1.113 PB", gb: 1113260.032 },
+        40: { label: "2.227 PB", gb: 2226520.064 },
+        41: { label: "4.453 PB", gb: 4453040.128 },
       },
       medium: {
         17: { label: "41.56 kB", gb: 0.000040 },