fs: simplify the error context collection in C++

- Simplify the SyncCall template function, only collect error
  number and syscall in the C++ layer and collect the rest of context
  in JS for flexibility.
- Remove the stringFromPath JS helper now that the unprefixed path is
  directly put into the context before the binding is invoked with the
  prefixed path.
- Validate more properties in fs.access tests.

PR-URL: https://github.com/nodejs/node/pull/17338
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

2 files changed, 16 insertions, 23 deletions

diff --git a/lib/fs.js b/lib/fs.js
index 93be375334..f357ff2b9d 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -329,10 +329,10 @@ fs.accessSync = function(path, mode) {
   else
     mode = mode | 0;
 
-  const ctx = {};
+  const ctx = { path };
   binding.access(pathModule.toNamespacedPath(path), mode, undefined, ctx);
 
-  if (ctx.code !== undefined) {
+  if (ctx.errno !== undefined) {
     throw new errors.uvException(ctx);
   }
 };
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 9e3d1a9355..db501a1d3c 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -14,6 +14,7 @@ const kCode = Symbol('code');
 const kInfo = Symbol('info');
 const messages = new Map();
 
+const { errmap } = process.binding('uv');
 const { kMaxLength } = process.binding('buffer');
 const { defineProperty } = Object;
 
@@ -194,43 +195,35 @@ function E(sym, val) {
   messages.set(sym, typeof val === 'function' ? val : String(val));
 }
 
-// JS counterpart of StringFromPath, although here path is a buffer.
-function stringFromPath(path) {
-  const str = path.toString();
-  if (process.platform !== 'win32') {
-    return str;
-  }
-
-  if (str.startsWith('\\\\?\\UNC\\')) {
-    return '\\\\' + str.slice(8);
-  } else if (str.startsWith('\\\\?\\')) {
-    return str.slice(4);
-  }
-  return str;
-}
-
 // This creates an error compatible with errors produced in UVException
 // using the context collected in CollectUVExceptionInfo
 // The goal is to migrate them to ERR_* errors later when
 // compatibility is not a concern
 function uvException(ctx) {
   const err = new Error();
-  err.errno = ctx.errno;
-  err.code = ctx.code;
-  err.syscall = ctx.syscall;
 
-  let message = `${ctx.code}: ${ctx.message}, ${ctx.syscall}`;
+  for (const prop of Object.keys(ctx)) {
+    if (prop === 'message' || prop === 'path' || prop === 'dest') {
+      continue;
+    }
+    err[prop] = ctx[prop];
+  }
+
+  const [ code, uvmsg ] = errmap.get(ctx.errno);
+  err.code = code;
+  let message = `${code}: ${uvmsg}, ${ctx.syscall}`;
   if (ctx.path) {
-    const path = stringFromPath(ctx.path);
+    const path = ctx.path.toString();
     message += ` '${path}'`;
     err.path = path;
   }
   if (ctx.dest) {
-    const dest = stringFromPath(ctx.dest);
+    const dest = ctx.dest.toString();
     message += ` -> '${dest}'`;
     err.dest = dest;
   }
   err.message = message;
+
   Error.captureStackTrace(err, uvException);
   return err;
 }