Make global imports map behave as default (#3)

README.md

@@ -46,7 +46,7 @@ Options include:
 
 ```js
 {
-  // An additional "imports" map to apply to all specifiers. Follows the same
+  // A default "imports" map to apply to all specifiers. Follows the same
   // syntax and rules as the "imports" property defined in `package.json`.
   imports,
   // A list of builtin module specifiers. If matched, the protocol of the
@@ -109,31 +109,34 @@ Options are the same as `resolve()` for all functions.
 2.  If `options.resolutions` is set:
     1.  If `preresolved(specifier, options.resolutions, parentURL, options)` returns `true`:
         1.  Return `true`.
-3.  If `options.imports` is set:
-    1.  If `packageImportsExports(specifier, options.imports, parentURL, true, options)` returns `true`:
-        1.  Return `true`.
 4.  If `url(specifier, parentURL, options)` returns `true`:
     1.  Return `true`.
 5.  If `packageImports(specifier, parentURL, options)` returns `true`:
     1.  Return `true`.
 6.  If `specifier` equals `.` or `..`, or if `specifier` starts with `/`, `\`, `./`, `.\`, `../`, or `..\`:
-    1.  Let `yielded` be `false`.
-    2.  If `file(specifier, parentURL, false, options)` returns `true`:
+    1.  If `options.imports` is set:
+        1.  If `packageImportsExports(specifier, options.imports, parentURL, true, options)` returns `true`:
+            1.  Return `true`.
+    2.  Let `yielded` be `false`.
+    3.  If `file(specifier, parentURL, false, options)` returns `true`:
         1.  Set `yielded` to `true`.
-    3.  If `directory(specifier, parentURL, options)` returns `true`:
+    4.  If `directory(specifier, parentURL, options)` returns `true`:
         1.  Set `yielded` to `true`.
-    4.  Return `yielded`.
+    5.  Return `yielded`.
 7.  Return `package(specifier, parentURL, options)`.
 
 #### `const generator = resolve.url(url, parentURL[, options])`
 
 1.  If `url` is not a valid URL:
     1.  Return `false`.
-2.  If `url.protocol` equals `node:`:
+2.  If `options.imports` is set:
+    1.  If `packageImportsExports(url.href, options.imports, parentURL, true, options)` returns `true`:
+        1.  Return `true`.
+3.  If `url.protocol` equals `node:`:
     1.  Let `specifier` be `url.pathname`.
     2.  If `specifier` equals `.` or `..`, or if `specifier` starts with `/`, `\`, `./`, `.\`, `../`, or `..\`, throw.
     3.  Return `package(specifier, parentURL, options)`
-3.  Yield `url` and return `true`.
+4.  Yield `url` and return `true`.
 
 #### `const generator = resolve.preresolved(specifier, resolutions, parentURL[, options])`
 
@@ -220,7 +223,10 @@ Options are the same as `resolve()` for all functions.
                 1.  Return `true`.
         2.  If specifier starts with `#`, throw.
         3.  Return `false`.
-3.  Return `false`.
+3.  If `options.imports` is set:
+    1.  If `packageImportsExports(url.href, options.imports, parentURL, true, options)` returns `true`:
+        1.  Return `true`.
+4.  Return `false`.
 
 #### `const generator = resolve.packageImportsExports(matchKey, matchObject, packageURL, isImports[, options])`
 

index.js

@@ -66,12 +66,6 @@ exports.module = function * (specifier, parentURL, opts = {}) {
     }
   }
 
-  if (imports) {
-    if (yield * exports.packageImportsExports(specifier, imports, parentURL, true, opts)) {
-      return true
-    }
-  }
-
   if (yield * exports.url(specifier, parentURL, opts)) {
     return true
   }
@@ -81,6 +75,12 @@ exports.module = function * (specifier, parentURL, opts = {}) {
   }
 
   if (specifier === '.' || specifier === '..' || specifier[0] === '/' || specifier[0] === '\\' || specifier.startsWith('./') || specifier.startsWith('.\\') || specifier.startsWith('../') || specifier.startsWith('..\\')) {
+    if (imports) {
+      if (yield * exports.packageImportsExports(specifier, imports, parentURL, true, opts)) {
+        return true
+      }
+    }
+
     let yielded = false
 
     if (yield * exports.file(specifier, parentURL, false, opts)) {
@@ -98,13 +98,21 @@ exports.module = function * (specifier, parentURL, opts = {}) {
 }
 
 exports.url = function * (url, parentURL, opts = {}) {
+  const { imports = null } = opts
+
   let resolution
   try {
     resolution = new URL(url)
   } catch {
     return false
   }
 
+  if (imports) {
+    if (yield * exports.packageImportsExports(resolution.href, imports, parentURL, true, opts)) {
+      return true
+    }
+  }
+
   if (resolution.protocol === 'node:') {
     const specifier = resolution.pathname
 
@@ -257,6 +265,8 @@ exports.packageExports = function * (packageURL, subpath, packageExports, opts =
 }
 
 exports.packageImports = function * (specifier, parentURL, opts = {}) {
+  const { imports = null } = opts
+
   if (specifier === '#' || specifier.startsWith('#/')) {
     throw errors.INVALID_MODULE_SPECIFIER(`Module specifier '${specifier}' is not a valid internal imports specifier`)
   }
@@ -279,6 +289,12 @@ exports.packageImports = function * (specifier, parentURL, opts = {}) {
     }
   }
 
+  if (imports) {
+    if (yield * exports.packageImportsExports(specifier, imports, parentURL, true, opts)) {
+      return true
+    }
+  }
+
   return false
 }
 

test.js

@@ -1069,6 +1069,32 @@ test('imports override with relative specifier', (t) => {
   t.alike(result, ['file:///a/b/e.js'])
 })
 
+test('imports override with package.json#imports', (t) => {
+  function readPackage (url) {
+    if (url.href === 'file:///a/b/c/package.json') {
+      return {
+        imports: {
+          './d': './f.js'
+        }
+      }
+    }
+
+    return null
+  }
+
+  const imports = {
+    './d': './e.js'
+  }
+
+  const result = []
+
+  for (const resolution of resolve('./d', new URL('file:///a/b/c/'), { imports }, readPackage)) {
+    result.push(resolution.href)
+  }
+
+  t.alike(result, ['file:///a/b/c/f.js'])
+})
+
 test('scoped package.json inside package', (t) => {
   function readPackage (url) {
     if (url.href === 'file:///a/b/node_modules/d/e/package.json') {