GEN-1: add vitest + exact Fraction utility

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-05 23:37:53 +02:00
parent 9b9cf2b35a
commit 2b9a0cd648
3 changed files with 448 additions and 3 deletions
--- a/gerbil-manager-web/package-lock.json
+++ b/gerbil-manager-web/package-lock.json
@@ -24,7 +24,8 @@
        "globals": "^17.6.0",
        "typescript": "~6.0.2",
        "typescript-eslint": "^8.59.2",
-        "vite": "^8.0.12"
+        "vite": "^8.0.12",
+        "vitest": "^4.1.8"
      }
    },
    "node_modules/@babel/code-frame": {
@@ -838,6 +839,13 @@
      "dev": true,
      "license": "MIT"
    },
+    "node_modules/@standard-schema/spec": {
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+      "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
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+      "dev": true,
+      "license": "MIT"
+    },
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      "version": "0.10.2",
      "resolved": "https://registry.npmjs.org/@tybys/wasm-util/-/wasm-util-0.10.2.tgz",
@@ -849,6 +857,24 @@
        "tslib": "^2.4.0"
      }
    },
+    "node_modules/@types/chai": {
+      "version": "5.2.3",
+      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/deep-eql": "*",
+        "assertion-error": "^2.0.1"
+      }
+    },
+    "node_modules/@types/deep-eql": {
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
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+      "dev": true,
+      "license": "MIT"
+    },
    "node_modules/@types/esrecurse": {
      "version": "4.3.1",
      "resolved": "https://registry.npmjs.org/@types/esrecurse/-/esrecurse-4.3.1.tgz",
@@ -1169,6 +1195,119 @@
        }
      }
    },
+    "node_modules/@vitest/expect": {
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.8.tgz",
+      "integrity": "sha512-h3nDO677RDLEGlBxyQ5CW8RlMThSKSRLUePLOx09gNIWRL40edgA1GCZSZgf1W55MFAG6/Sw14KeaAnqv0NKdQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@standard-schema/spec": "^1.1.0",
+        "@types/chai": "^5.2.2",
+        "@vitest/spy": "4.1.8",
+        "@vitest/utils": "4.1.8",
+        "chai": "^6.2.2",
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/mocker": {
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.1.8.tgz",
+      "integrity": "sha512-LEiN/xe4OSIbKe9HQIp5OC24agGD9J5CnmMgsLohVVoOPWL9a2sBoR6VBx43jQZb7Kr1l4RCuyCJzcAa0+dojw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/spy": "4.1.8",
+        "estree-walker": "^3.0.3",
+        "magic-string": "^0.30.21"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "msw": "^2.4.9",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "msw": {
+          "optional": true
+        },
+        "vite": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/@vitest/pretty-format": {
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.8.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/runner": {
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/utils": "4.1.8",
+        "pathe": "^2.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/snapshot": {
+      "version": "4.1.8",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
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+        "@vitest/utils": "4.1.8",
+        "magic-string": "^0.30.21",
+        "pathe": "^2.0.3"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
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+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
+    "node_modules/@vitest/utils": {
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.8.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/pretty-format": "4.1.8",
+        "convert-source-map": "^2.0.0",
+        "tinyrainbow": "^3.1.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      }
+    },
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      "version": "8.16.0",
      "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.16.0.tgz",
@@ -1209,6 +1348,16 @@
        "url": "https://github.com/sponsors/epoberezkin"
      }
    },
+    "node_modules/assertion-error": {
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+      "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      }
+    },
    "node_modules/balanced-match": {
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      "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-4.0.4.tgz",
@@ -1300,6 +1449,16 @@
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      "license": "CC-BY-4.0"
    },
+    "node_modules/chai": {
+      "version": "6.2.2",
+      "resolved": "https://registry.npmjs.org/chai/-/chai-6.2.2.tgz",
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+      "license": "MIT",
+      "engines": {
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@@ -1384,6 +1543,13 @@
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      "license": "ISC"
    },
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@@ -1579,6 +1745,16 @@
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
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+      }
+    },
    "node_modules/esutils": {
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      "resolved": "https://registry.npmjs.org/esutils/-/esutils-2.0.3.tgz",
@@ -1589,6 +1765,16 @@
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      }
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+      "resolved": "https://registry.npmjs.org/expect-type/-/expect-type-1.3.0.tgz",
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+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
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+      }
+    },
    "node_modules/fast-deep-equal": {
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      "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
@@ -2162,6 +2348,16 @@
        "yallist": "^3.0.2"
      }
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+    "node_modules/magic-string": {
+      "version": "0.30.21",
+      "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
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+      "license": "MIT",
+      "dependencies": {
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+    },
    "node_modules/minimatch": {
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      "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-10.2.5.tgz",
@@ -2221,6 +2417,20 @@
        "node": ">=18"
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    },
+    "node_modules/obug": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/obug/-/obug-2.1.2.tgz",
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+      "dev": true,
+      "funding": [
+        "https://github.com/sponsors/sxzz",
+        "https://opencollective.com/debug"
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      }
+    },
    "node_modules/optionator": {
      "version": "0.9.4",
      "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.9.4.tgz",
@@ -2291,6 +2501,13 @@
        "node": ">=8"
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+      "resolved": "https://registry.npmjs.org/pathe/-/pathe-2.0.3.tgz",
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+      "license": "MIT"
+    },
    "node_modules/picocolors": {
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      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
@@ -2498,6 +2715,13 @@
        "node": ">=8"
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+    "node_modules/siginfo": {
+      "version": "2.0.0",
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+      "license": "ISC"
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@@ -2508,6 +2732,37 @@
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+    "node_modules/stackback": {
+      "version": "0.0.2",
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+      "license": "MIT"
+    },
+    "node_modules/std-env": {
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+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/tinybench": {
+      "version": "2.9.0",
+      "resolved": "https://registry.npmjs.org/tinybench/-/tinybench-2.9.0.tgz",
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+      "license": "MIT"
+    },
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+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      }
+    },
    "node_modules/tinyglobby": {
      "version": "0.2.17",
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@@ -2525,6 +2780,16 @@
        "url": "https://github.com/sponsors/SuperchupuDev"
      }
    },
+    "node_modules/tinyrainbow": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.0.tgz",
+      "integrity": "sha512-Bf+ILmBgretUrdJxzXM0SgXLZ3XfiaUuOj/IKQHuTXip+05Xn+uyEYdVg0kYDipTBcLrCVyUzAPz7QmArb0mmw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
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    "node_modules/ts-api-utils": {
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@@ -2723,6 +2988,96 @@
        }
      }
    },
+    "node_modules/vitest": {
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/vitest/-/vitest-4.1.8.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@vitest/expect": "4.1.8",
+        "@vitest/mocker": "4.1.8",
+        "@vitest/pretty-format": "4.1.8",
+        "@vitest/runner": "4.1.8",
+        "@vitest/snapshot": "4.1.8",
+        "@vitest/spy": "4.1.8",
+        "@vitest/utils": "4.1.8",
+        "es-module-lexer": "^2.0.0",
+        "expect-type": "^1.3.0",
+        "magic-string": "^0.30.21",
+        "obug": "^2.1.1",
+        "pathe": "^2.0.3",
+        "picomatch": "^4.0.3",
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+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0",
+        "why-is-node-running": "^2.3.0"
+      },
+      "bin": {
+        "vitest": "vitest.mjs"
+      },
+      "engines": {
+        "node": "^20.0.0 || ^22.0.0 || >=24.0.0"
+      },
+      "funding": {
+        "url": "https://opencollective.com/vitest"
+      },
+      "peerDependencies": {
+        "@edge-runtime/vm": "*",
+        "@opentelemetry/api": "^1.9.0",
+        "@types/node": "^20.0.0 || ^22.0.0 || >=24.0.0",
+        "@vitest/browser-playwright": "4.1.8",
+        "@vitest/browser-preview": "4.1.8",
+        "@vitest/browser-webdriverio": "4.1.8",
+        "@vitest/coverage-istanbul": "4.1.8",
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+        "@vitest/ui": "4.1.8",
+        "happy-dom": "*",
+        "jsdom": "*",
+        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@edge-runtime/vm": {
+          "optional": true
+        },
+        "@opentelemetry/api": {
+          "optional": true
+        },
+        "@types/node": {
+          "optional": true
+        },
+        "@vitest/browser-playwright": {
+          "optional": true
+        },
+        "@vitest/browser-preview": {
+          "optional": true
+        },
+        "@vitest/browser-webdriverio": {
+          "optional": true
+        },
+        "@vitest/coverage-istanbul": {
+          "optional": true
+        },
+        "@vitest/coverage-v8": {
+          "optional": true
+        },
+        "@vitest/ui": {
+          "optional": true
+        },
+        "happy-dom": {
+          "optional": true
+        },
+        "jsdom": {
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@@ -2739,6 +3094,23 @@
        "node": ">= 8"
      }
    },
+    "node_modules/why-is-node-running": {
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "siginfo": "^2.0.0",
+        "stackback": "0.0.2"
+      },
+      "bin": {
+        "why-is-node-running": "cli.js"
+      },
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      "version": "1.2.5",
      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.5.tgz",
--- a/gerbil-manager-web/package.json
+++ b/gerbil-manager-web/package.json
@@ -7,7 +7,9 @@
    "dev": "vite",
    "build": "tsc -b && vite build",
    "lint": "eslint .",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest run",
+    "test:watch": "vitest"
  },
  "dependencies": {
    "react": "^19.2.6",
@@ -26,6 +28,7 @@
    "globals": "^17.6.0",
    "typescript": "~6.0.2",
    "typescript-eslint": "^8.59.2",
-    "vite": "^8.0.12"
+    "vite": "^8.0.12",
+    "vitest": "^4.1.8"
  }
 }
--- a/gerbil-manager-web/src/genetics/fraction.ts
+++ b/gerbil-manager-web/src/genetics/fraction.ts
@@ -0,0 +1,70 @@
+/**
+ * Exact rational arithmetic for genetics probabilities.
+ *
+ * Punnett distributions are unions of dyadic/rational fractions (1/4, 3/16, …).
+ * Using exact fractions instead of floats keeps probabilities precise and lets
+ * us assert e.g. "exactly 1/4 of young are lost" after renormalisation.
+ */
+export interface Fraction {
+  readonly num: number
+  readonly den: number
+}
+
+function gcd(a: number, b: number): number {
+  a = Math.abs(a)
+  b = Math.abs(b)
+  while (b !== 0) {
+    ;[a, b] = [b, a % b]
+  }
+  return a
+}
+
+/** Create a normalised (reduced, positive-denominator) fraction. */
+export function frac(num: number, den: number): Fraction {
+  if (den === 0) throw new Error('Fraction denominator must not be zero')
+  if (den < 0) {
+    num = -num
+    den = -den
+  }
+  if (num === 0) return { num: 0, den: 1 }
+  const g = gcd(num, den)
+  return { num: num / g, den: den / g }
+}
+
+export const ZERO: Fraction = { num: 0, den: 1 }
+export const ONE: Fraction = { num: 1, den: 1 }
+
+export function add(a: Fraction, b: Fraction): Fraction {
+  return frac(a.num * b.den + b.num * a.den, a.den * b.den)
+}
+
+export function multiply(a: Fraction, b: Fraction): Fraction {
+  return frac(a.num * b.num, a.den * b.den)
+}
+
+export function divide(a: Fraction, b: Fraction): Fraction {
+  if (b.num === 0) throw new Error('Cannot divide by zero fraction')
+  return frac(a.num * b.den, a.den * b.num)
+}
+
+export function equals(a: Fraction, b: Fraction): boolean {
+  return a.num * b.den === b.num * a.den
+}
+
+export function toNumber(f: Fraction): number {
+  return f.num / f.den
+}
+
+/** Human-readable "3/16" (or "0" / "1"). */
+export function toString(f: Fraction): string {
+  if (f.num === 0) return '0'
+  if (f.den === 1) return String(f.num)
+  return `${f.num}/${f.den}`
+}
+
+/** "18.75 %" style label for display (rounded to `digits` decimals). */
+export function toPercentString(f: Fraction, digits = 2): string {
+  const pct = (f.num / f.den) * 100
+  const rounded = Number(pct.toFixed(digits))
+  return `${rounded} %`
+}