fix(no-missing-import): Support data imports

Imported prefixed with 'data:' are not modules to be resolved, but the
direct data that should be imported (e.g., JavaScript code, JSON or
WASM).

This PR adds support for such imports in the no-missing-import rule.

Note:
With this change, the rule doesn't attempt to parse the data being
imported, it merely does not try to resolve it to a path (which would
fail), and thus allows those imports in the user's code.

Fixes #464

Author: mureinik

lib/util/import-target.js

@@ -74,7 +74,7 @@ function getTSConfigAliases(context) {
  * @property {Partial<import('enhanced-resolve').ResolveOptions>} [resolverConfig]
  * @property {string} basedir
  */
-/** @typedef { 'unknown' | 'relative' | 'absolute' | 'node' | 'npm' | 'http' } ModuleType */
+/** @typedef { 'unknown' | 'relative' | 'absolute' | 'node' | 'npm' | 'http' | 'data' } ModuleType */
 /** @typedef { 'import' | 'require' | 'type' } ModuleStyle */
 
 /**
@@ -176,6 +176,10 @@ module.exports = class ImportTarget {
             return "node"
         }
 
+        if (/^data:/.test(this.name)) {
+            return "data"
+        }
+
         if (/^(@[\w~-][\w.~-]*\/)?[\w~-][\w.~-]*/.test(this.name)) {
             return "npm"
         }
@@ -242,7 +246,7 @@ module.exports = class ImportTarget {
      * @returns {string | undefined}
      */
     getModuleName() {
-        if (this.moduleType === "relative") return
+        if (this.moduleType === "relative" || this.moduleType === "data") return
 
         if (this.moduleType === "npm") {
             if (this.name.startsWith("@")) {
@@ -349,6 +353,10 @@ module.exports = class ImportTarget {
                 ? this.context.settings?.cwd
                 : process.cwd()
 
+        if (this.moduleType === "data") {
+            return this.name
+        }
+
         for (const directory of this.getPaths()) {
             const baseDir = resolve(cwd, directory)
 

tests/lib/rules/no-missing-import.js

@@ -366,6 +366,12 @@ ruleTester.run("no-missing-import", rule, {
             options: [{ ignoreTypeImport: true }],
         },
 
+        // data import
+        {
+            filename: fixture("test.js"),
+            code: "import 'data:text/javascript,const x = 123;';",
+        },
+
         // import()
         ...(DynamicImportSupported
             ? [