From 6683109d06ab937dfbb9a615a74882d3e2922c1a Mon Sep 17 00:00:00 2001
From: Sohil Kshirsagar <sohil@usetusk.ai>
Date: Wed, 6 May 2026 17:37:10 -0700
Subject: [PATCH 1/2] fix(coverage): use dynamic import for ast-v8-to-istanbul
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ast-v8-to-istanbul is ESM-only and pulls in estree-walker, whose
package.json `exports` field has no `require` condition. Under tsx's
ESM loader, `require("ast-v8-to-istanbul")` resolves transitive imports
with the require condition and dies on estree-walker with
ERR_PACKAGE_PATH_NOT_EXPORTED — every coverage snapshot fails and no
data is uploaded.

Switching to dynamic `await import()` resolves with the import
condition throughout and works under both plain Node and tsx.
---
 src/core/coverageProcessor.ts | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/core/coverageProcessor.ts b/src/core/coverageProcessor.ts
index b04afb1..72ce9a1 100644
--- a/src/core/coverageProcessor.ts
+++ b/src/core/coverageProcessor.ts
@@ -258,10 +258,13 @@ export async function processV8CoverageFile(
   includeAll: boolean = false,
   preParsedData?: V8CoverageData,
 ): Promise<CoverageResult> {
-  // Lazy-loaded: these are only needed when coverage is enabled, which is opt-in.
-  // Using require() avoids loading them on every SDK startup (adds ~50ms + memory).
-  // eslint-disable-next-line @typescript-eslint/no-var-requires
-  const { convert } = require("ast-v8-to-istanbul");
+  // Lazy-loaded: only needed when coverage is enabled (opt-in), saves ~50ms + memory at SDK startup.
+  // Using dynamic import (not require) because ast-v8-to-istanbul is ESM-only and pulls in
+  // estree-walker, whose package.json `exports` field has no `require` condition. Under tsx's
+  // ESM loader, `require("ast-v8-to-istanbul")` resolves transitive imports with the require
+  // condition and dies on estree-walker with ERR_PACKAGE_PATH_NOT_EXPORTED. Dynamic import
+  // resolves with the import condition throughout and works under both plain Node and tsx.
+  const { convert } = await import("ast-v8-to-istanbul");
   const data: V8CoverageData = preParsedData ?? JSON.parse(fs.readFileSync(v8FilePath, "utf-8"));
   const coverage: CoverageResult = {};
 

From fa0fad86e2fb3ca8a8ba52f66671446c2b6e886c Mon Sep 17 00:00:00 2001
From: Sohil Kshirsagar <sohil@usetusk.ai>
Date: Wed, 6 May 2026 17:46:09 -0700
Subject: [PATCH 2/2] fix(coverage): tighten V8FunctionCoverage type and adjust
 source-map cast

Tighten V8FunctionCoverage to match Node's Profiler.FunctionCoverage
contract (functionName and isBlockCoverage are always emitted by V8),
which lets script.functions pass through to ast-v8-to-istanbul.convert
without a cast. Update the test fixture accordingly. Source map still
needs a cast since loadSourceMap returns Record<string, unknown>.
---
 src/core/coverageProcessor.test.ts |  1 +
 src/core/coverageProcessor.ts      | 11 ++++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/core/coverageProcessor.test.ts b/src/core/coverageProcessor.test.ts
index 155d2a7..b8abdb5 100644
--- a/src/core/coverageProcessor.test.ts
+++ b/src/core/coverageProcessor.test.ts
@@ -60,6 +60,7 @@ test("takeAndProcessSnapshot: skips coverage files without user scripts", async
             {
               functionName: "",
               ranges: [{ startOffset: 0, endOffset: 10, count: 1 }],
+              isBlockCoverage: false,
             },
           ],
         },
diff --git a/src/core/coverageProcessor.ts b/src/core/coverageProcessor.ts
index 72ce9a1..7867e47 100644
--- a/src/core/coverageProcessor.ts
+++ b/src/core/coverageProcessor.ts
@@ -38,9 +38,11 @@ export interface V8CoverageRange {
 }
 
 export interface V8FunctionCoverage {
-  functionName?: string;
+  // V8 always emits these per Node's Profiler.FunctionCoverage contract; matching that
+  // shape lets us pass V8FunctionCoverage[] to ast-v8-to-istanbul.convert without a cast.
+  functionName: string;
   ranges: V8CoverageRange[];
-  isBlockCoverage?: boolean;
+  isBlockCoverage: boolean;
 }
 
 export interface V8ScriptCoverage {
@@ -331,7 +333,10 @@ export async function processV8CoverageFile(
         code: codeForConvert,
         ast,
         coverage: { functions: script.functions, url: script.url },
-        ...(sourceMap ? { sourceMap } : {}),
+        // sourceMap is parsed JSON — loadSourceMap returns Record<string, unknown> rather
+        // than committing to a specific source-map type from a transitive dep. Cast to the
+        // shape convert expects.
+        ...(sourceMap ? { sourceMap: sourceMap as Parameters<typeof convert>[0]["sourceMap"] } : {}),
         ...(cjsWrapperLength ? { wrapperLength: cjsWrapperLength } : {}),
       });