feat: findTypeImports for finding type imports (#163)

src/_utils.ts

@@ -43,3 +43,24 @@ export function matchAll(regex, string, addition) {
   }
   return matches;
 }
+
+export function clearImports(imports: string) {
+  return (imports || "")
+    .replace(/(\/\/[^\n]*\n|\/\*.*\*\/)/g, "")
+    .replace(/\s+/g, " ");
+}
+
+export function getImportNames(cleanedImports: string) {
+  const topLevelImports = cleanedImports.replace(/{([^}]*)}/, "");
+  const namespacedImport = topLevelImports.match(/\* as \s*(\S*)/)?.[1];
+  const defaultImport =
+    topLevelImports
+      .split(",")
+      .find((index) => !/[*{}]/.test(index))
+      ?.trim() || undefined;
+
+  return {
+    namespacedImport,
+    defaultImport,
+  };
+}

src/analyze.ts

@@ -1,5 +1,5 @@
 import { tokenizer } from "acorn";
-import { matchAll } from "./_utils";
+import { matchAll, clearImports, getImportNames } from "./_utils";
 import { resolvePath, ResolveOptions } from "./resolve";
 import { loadURL } from "./utils";
 
@@ -27,6 +27,12 @@ export interface DynamicImport extends ESMImport {
   expression: string;
 }
 
+export interface TypeImport extends Omit<ESMImport, "type"> {
+  type: "type";
+  imports: string;
+  specifier: string;
+}
+
 export interface ESMExport {
   _type?: "declaration" | "named" | "default" | "star";
   type: "declaration" | "named" | "default" | "star";
@@ -59,6 +65,8 @@ export const ESM_STATIC_IMPORT_RE =
   /(?<=\s|^|;)import\s*([\s"']*(?<imports>[\p{L}\p{M}\w\t\n\r $*,/{}]+)from\s*)?["']\s*(?<specifier>(?<="\s*)[^"]*[^\s"](?=\s*")|(?<='\s*)[^']*[^\s'](?=\s*'))\s*["'][\s;]*/gmu;
 export const DYNAMIC_IMPORT_RE =
   /import\s*\((?<expression>(?:[^()]+|\((?:[^()]+|\([^()]*\))*\))*)\)/gm;
+const IMPORT_NAMED_TYPE_RE =
+  /(?<=\s|^|;)import\s*type\s+([\s"']*(?<imports>[\w\t\n\r $*,/{}]+)from\s*)?["']\s*(?<specifier>(?<="\s*)[^"]*[^\s"](?=\s*")|(?<='\s*)[^']*[^\s'](?=\s*'))\s*["'][\s;]*/gm;
 
 export const EXPORT_DECAL_RE =
   /\bexport\s+(?<declaration>(async function|function|let|const enum|const|enum|var|class))\s+(?<name>[\w$]+)/g;
@@ -83,10 +91,19 @@ export function findDynamicImports(code: string): DynamicImport[] {
   return matchAll(DYNAMIC_IMPORT_RE, code, { type: "dynamic" });
 }
 
-export function parseStaticImport(matched: StaticImport): ParsedStaticImport {
-  const cleanedImports = (matched.imports || "")
-    .replace(/(\/\/[^\n]*\n|\/\*.*\*\/)/g, "")
-    .replace(/\s+/g, " ");
+export function findTypeImports(code: string): TypeImport[] {
+  return [
+    ...matchAll(IMPORT_NAMED_TYPE_RE, code, { type: "type" }),
+    ...matchAll(ESM_STATIC_IMPORT_RE, code, { type: "static" }).filter(
+      (match) => /[^A-Za-z]type\s/.test(match.imports)
+    ),
+  ];
+}
+
+export function parseStaticImport(
+  matched: StaticImport | TypeImport
+): ParsedStaticImport {
+  const cleanedImports = clearImports(matched.imports);
 
   const namedImports = {};
   for (const namedImport of cleanedImports
@@ -98,13 +115,41 @@ export function parseStaticImport(matched: StaticImport): ParsedStaticImport {
       namedImports[source] = importName;
     }
   }
-  const topLevelImports = cleanedImports.replace(/{([^}]*)}/, "");
-  const namespacedImport = topLevelImports.match(/\* as \s*(\S*)/)?.[1];
-  const defaultImport =
-    topLevelImports
-      .split(",")
-      .find((index) => !/[*{}]/.test(index))
-      ?.trim() || undefined;
+  const { namespacedImport, defaultImport } = getImportNames(cleanedImports);
+
+  return {
+    ...matched,
+    defaultImport,
+    namespacedImport,
+    namedImports,
+  } as ParsedStaticImport;
+}
+
+export function parseTypeImport(
+  matched: TypeImport | StaticImport
+): ParsedStaticImport {
+  if (matched.type === "type") {
+    return parseStaticImport(matched);
+  }
+
+  const cleanedImports = clearImports(matched.imports);
+
+  const namedImports = {};
+  for (const namedImport of cleanedImports
+    .match(/{([^}]*)}/)?.[1]
+    ?.split(",") || []) {
+    const [, source = namedImport.trim(), importName = source] = (() => {
+      return /\s+as\s+/.test(namedImport)
+        ? namedImport.match(/^\s*type\s+(\S*) as (\S*)\s*$/) || []
+        : namedImport.match(/^\s*type\s+(\S*)\s*$/) || [];
+    })();
+
+    if (source && TYPE_RE.test(namedImport)) {
+      namedImports[source] = importName;
+    }
+  }
+
+  const { namespacedImport, defaultImport } = getImportNames(cleanedImports);
 
   return {
     ...matched,

src/utils.ts

@@ -1,6 +1,7 @@
 import { fileURLToPath as _fileURLToPath } from "node:url";
 import { promises as fsp } from "node:fs";
 import { normalizeSlash, BUILTIN_MODULES } from "./_utils";
+import { StaticImport, TypeImport } from "./analyze";
 
 export function fileURLToPath(id: string): string {
   if (typeof id === "string" && !id.startsWith("file://")) {

test/imports.test.ts

@@ -3,6 +3,8 @@ import {
   findDynamicImports,
   findStaticImports,
   parseStaticImport,
+  findTypeImports,
+  parseTypeImport,
 } from "../src";
 
 // -- Static import --
@@ -153,6 +155,57 @@ const dynamicTests = {
   },
 };
 
+const TypeTests = {
+  'import { type Foo, Bar } from "module-name";': {
+    specifier: "module-name",
+    namedImports: {
+      Foo: "Foo",
+    },
+    type: "static",
+  },
+  'import { member,/* hello */  type Foo as Baz, Bar } from "module-name";': {
+    specifier: "module-name",
+    namedImports: {
+      Foo: "Baz",
+    },
+    type: "static",
+  },
+  'import type { Foo, Bar } from "module-name";': {
+    specifier: "module-name",
+    namedImports: {
+      Foo: "Foo",
+      Bar: "Bar",
+    },
+    type: "type",
+  },
+  'import type Foo from "module-name";': {
+    specifier: "module-name",
+    defaultImport: "Foo",
+    type: "type",
+  },
+  'import type { Foo as Baz, Bar } from "module-name";': {
+    specifier: "module-name",
+    namedImports: {
+      Foo: "Baz",
+      Bar: "Bar",
+    },
+    type: "type",
+  },
+  'import { type member } from "  module-name";': {
+    specifier: "module-name",
+    namedImports: { member: "member" },
+    type: "static",
+  },
+  'import { type member, type Foo as Bar } from "  module-name";': {
+    specifier: "module-name",
+    namedImports: {
+      member: "member",
+      Foo: "Bar",
+    },
+    type: "static",
+  },
+};
+
 describe("findStaticImports", () => {
   for (const [input, _results] of Object.entries(staticTests)) {
     it(input.replace(/\n/g, "\\n"), () => {
@@ -191,3 +244,31 @@ describe("findDynamicImports", () => {
     });
   }
 });
+
+describe("findTypeImports", () => {
+  for (const [input, _results] of Object.entries(TypeTests)) {
+    it(input.replace(/\n/g, "\\n"), () => {
+      const matches = findTypeImports(input);
+      const results = Array.isArray(_results) ? _results : [_results];
+      expect(matches.length).toEqual(results.length);
+      for (const [index, test] of results.entries()) {
+        const match = matches[index];
+        expect(match.specifier).to.equal(test.specifier);
+
+        const parsed = parseTypeImport(match);
+        if (test.type) {
+          expect(parsed.type).to.equals(test.type);
+        }
+        if (test.defaultImport) {
+          expect(parsed.defaultImport).to.equals(test.defaultImport);
+        }
+        if (test.namedImports) {
+          expect(parsed.namedImports).to.eql(test.namedImports);
+        }
+        if (test.namespacedImport) {
+          expect(parsed.namespacedImport).to.eql(test.namespacedImport);
+        }
+      }
+    });
+  }
+});