feat: ✨ implement the coverage reporter with the LLM friend

Author: cif

package.json

@@ -4,8 +4,7 @@
   "description": "A plugin for vitest that generates a coverage summary in json format",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1",
-    "coverage": "vitest run --coverage"
+    "test": "vitest run --coverage"
   },
   "author": "Typeguard Inc.",
   "license": "MIT",

src/v8.json.summary.reporter.test.ts

@@ -0,0 +1,231 @@
+import { describe, it, expect } from "vitest";
+import { generateV8CoverageSummary } from "./v8.json.summary.reporter";
+
+describe("generateV8CoverageSummary", () => {
+  it("should generate correct summary for 100% coverage", () => {
+    const mockCoverage = {
+      data: {
+        "test.js": {
+          path: "/test.js",
+          s: { "0": 1, "1": 1, "2": 1 },
+          f: { "0": 1 },
+          b: { "0": [1, 1] },
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+            "2": { start: { line: 3 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.summary.statements).toBe(100);
+    expect(summary.summary.branches).toBe(100);
+    expect(summary.summary.functions).toBe(100);
+    expect(summary.summary.lines).toBe(100);
+    expect(summary.files).toHaveLength(1);
+    expect(summary.files[0].statements).toBe(100);
+    expect(summary.files[0].branches).toBe(100);
+    expect(summary.files[0].functions).toBe(100);
+    expect(summary.files[0].lines).toBe(100);
+    expect(summary.files[0].uncoveredLines).toBeUndefined();
+  });
+
+  it("should generate correct summary for partial coverage", () => {
+    const mockCoverage = {
+      data: {
+        "test.js": {
+          path: "/test.js",
+          s: { "0": 1, "1": 0, "2": 1, "3": 0 },
+          f: { "0": 1, "1": 0 },
+          b: { "0": [1, 0], "1": [0, 0] },
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+            "2": { start: { line: 3 } },
+            "3": { start: { line: 4 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.summary.statements).toBe(50);
+    expect(summary.summary.branches).toBe(25);
+    expect(summary.summary.functions).toBe(50);
+    expect(summary.summary.lines).toBe(50);
+    expect(summary.files[0].statements).toBe(50);
+    expect(summary.files[0].branches).toBe(25);
+    expect(summary.files[0].functions).toBe(50);
+    expect(summary.files[0].lines).toBe(50);
+    expect(summary.files[0].uncoveredLines).toEqual([2, 4]);
+  });
+
+  it("should generate correct summary for 0% coverage", () => {
+    const mockCoverage = {
+      data: {
+        "test.js": {
+          path: "/test.js",
+          s: { "0": 0, "1": 0 },
+          f: { "0": 0 },
+          b: { "0": [0, 0] },
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.summary.statements).toBe(0);
+    expect(summary.summary.branches).toBe(0);
+    expect(summary.summary.functions).toBe(0);
+    expect(summary.summary.lines).toBe(0);
+    expect(summary.files[0].statements).toBe(0);
+    expect(summary.files[0].branches).toBe(0);
+    expect(summary.files[0].functions).toBe(0);
+    expect(summary.files[0].lines).toBe(0);
+    expect(summary.files[0].uncoveredLines).toEqual([1, 2]);
+  });
+
+  it("should handle multiple files correctly", () => {
+    const mockCoverage = {
+      data: {
+        "file1.js": {
+          path: "/file1.js",
+          s: { "0": 1, "1": 1 },
+          f: { "0": 1 },
+          b: { "0": [1, 1] },
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+          },
+        },
+        "file2.js": {
+          path: "/file2.js",
+          s: { "0": 0, "1": 1 },
+          f: { "0": 0, "1": 1 },
+          b: { "0": [0, 0] },
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.files).toHaveLength(2);
+    expect(summary.summary.statements).toBe(75); // (2+1)/(2+2) = 75
+    expect(summary.summary.branches).toBe(50); // (2/4) = 50
+    expect(summary.summary.functions).toBe(66.67); // (1+1)/(1+2) = 66.67
+    expect(summary.summary.lines).toBe(75); // Same as statements
+  });
+
+  it("should handle empty coverage data", () => {
+    const mockCoverage = { data: {} };
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.summary.statements).toBe(100);
+    expect(summary.summary.branches).toBe(100);
+    expect(summary.summary.functions).toBe(100);
+    expect(summary.summary.lines).toBe(100);
+    expect(summary.files).toHaveLength(0);
+  });
+
+  it("should handle files with missing coverage data", () => {
+    const mockCoverage = {
+      data: {
+        "valid.js": {
+          path: "/valid.js",
+          s: { "0": 1 },
+          f: { "0": 1 },
+          b: { "0": [1] },
+          statementMap: { "0": { start: { line: 1 } } },
+        },
+        "invalid.js": {
+          path: "/invalid.js",
+          // Missing s, f, b properties
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.files).toHaveLength(1);
+    expect(summary.files[0].file).toContain("valid.js");
+    expect(summary.summary.statements).toBe(100);
+  });
+
+  it("should handle coverage data without .data property", () => {
+    const mockCoverage = {
+      "test.js": {
+        path: "/test.js",
+        s: { "0": 1 },
+        f: { "0": 1 },
+        b: { "0": [1] },
+        statementMap: { "0": { start: { line: 1 } } },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.files).toHaveLength(1);
+    expect(summary.summary.statements).toBe(100);
+  });
+
+  it("should calculate percentages with proper rounding", () => {
+    const mockCoverage = {
+      data: {
+        "test.js": {
+          path: "/test.js",
+          s: { "0": 1, "1": 1, "2": 0 }, // 2/3 = 66.666...%
+          f: { "0": 1, "1": 0 }, // 1/2 = 50%
+          b: { "0": [1, 0], "1": [0, 0] }, // 1/4 = 25%
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+            "2": { start: { line: 3 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.files[0].statements).toBe(66.67); // Rounded to 2 decimal places
+    expect(summary.files[0].functions).toBe(50);
+    expect(summary.files[0].branches).toBe(25);
+    expect(summary.files[0].lines).toBe(66.67);
+  });
+
+  it("should handle files with no branches or functions", () => {
+    const mockCoverage = {
+      data: {
+        "simple.js": {
+          path: "/simple.js",
+          s: { "0": 1, "1": 0 },
+          f: {}, // No functions
+          b: {}, // No branches
+          statementMap: {
+            "0": { start: { line: 1 } },
+            "1": { start: { line: 2 } },
+          },
+        },
+      },
+    };
+
+    const summary = generateV8CoverageSummary(mockCoverage);
+
+    expect(summary.files[0].statements).toBe(50);
+    expect(summary.files[0].branches).toBe(100); // No branches = 100% coverage
+    expect(summary.files[0].functions).toBe(100); // No functions = 100% coverage
+    expect(summary.files[0].lines).toBe(50);
+  });
+});