Map exact c8 TypeScript if arms to EtsIR coverage

usvm-ts-fast-check/README.md

@@ -7,6 +7,20 @@ runtime.
 The public property model, validation, registries, coverage contracts and decoders, and property-to-EtsIR mapping
 remain in [`usvm-ts-pbt`](../usvm-ts-pbt/README.md).
 
+## Branch coverage boundary
+
+One c8 execution produces the existing source-mapped Istanbul statement report and raw V8 ranges. The bounded
+TypeScript branch converter reads those same raw ranges, the executed source snapshot, and the source map. It emits
+ordered `if` arms only when the original TypeScript points map back exactly, each arm has a distinct V8 execution
+point, and the arm counts add up to the count at the condition. A supported `if` without `else` additionally needs
+a single terminating `return` or `throw` in its true arm and a following statement that is reached only on false.
+Nested `if` statements are supported under those conditions. Ambiguous counts or ranges and unsupported constructs
+produce diagnostics; exact statement mappings remain available.
+
+Loops, `switch`, conditional expressions, logical short-circuit ranges, and function or script ranges are never
+reinterpreted as `if` arms. The converter does not instrument the TypeScript program or execute it a second time.
+The resulting edges are coverage artifacts; target-selection integration belongs to #399/#355.
+
 Run the backend checks with:
 
 ```shell

usvm-ts-fast-check/build.gradle.kts

@@ -11,6 +11,7 @@ dependencies {
     implementation(Libs.clikt)
     implementation(Libs.kotlinx_serialization_json)
 
+    testImplementation(Libs.jacodb_ets)
     testImplementation(Libs.logback)
 }
 

usvm-ts-fast-check/fast-check-adapter/package.json

@@ -9,16 +9,17 @@
     "build": "tsc --project tsconfig.json",
     "pretest": "npm run build",
     "test": "npm run test:compiled",
-    "test:compiled": "node --test dist/test/entry-point.test.js dist/test/local-source-closure.test.js dist/test/execute-property.test.js dist/test/execution-cli.test.js dist/test/js-value.test.js dist/test/process-group-shutdown.test.js dist/test/process-supervisor.test.js dist/test/project-domain.test.js dist/test/projection-cli.test.js"
+    "test:compiled": "node --test dist/test/coverage-branches.test.js dist/test/entry-point.test.js dist/test/local-source-closure.test.js dist/test/execute-property.test.js dist/test/execution-cli.test.js dist/test/js-value.test.js dist/test/process-group-shutdown.test.js dist/test/process-supervisor.test.js dist/test/project-domain.test.js dist/test/projection-cli.test.js"
   },
   "dependencies": {
+    "@jridgewell/trace-mapping": "0.3.31",
     "c8": "10.1.3",
     "fast-check": "4.9.0",
-    "tsx": "4.23.12"
+    "tsx": "4.23.12",
+    "typescript": "5.9.2"
   },
   "devDependencies": {
-    "@types/node": "18.19.130",
-    "typescript": "5.9.2"
+    "@types/node": "18.19.130"
   },
   "overrides": {
     "c8": {