feat: Ignore imports that are inside comments

src/parseComments.js

@@ -0,0 +1,56 @@
+/**
+ * @typedef CommentLocation
+ * @property {number} start
+ * @property {number} end
+ */
+
+/**
+ * @param {string} scriptSource
+ */
+export function getCommentLocations(scriptSource) {
+  /** @type {CommentLocation[]} */
+  const commentLocations = [];
+  let totalIndex = 0;
+  for (const line of scriptSource.split("\n")) {
+    const commentIndex = line.indexOf("//");
+    if (commentIndex >= 0) {
+      commentLocations.push({
+        start: totalIndex + commentIndex,
+        end: totalIndex + line.length,
+      });
+    }
+    totalIndex += line.length + "\n".length;
+  }
+
+  const blockCommentRegex = /\/\*[\s\S]*\*\//g;
+  for (const match of scriptSource.matchAll(blockCommentRegex)) {
+    if (match.index == undefined) continue;
+    commentLocations.push({
+      start: match.index,
+      end: match.index + match[0].length,
+    });
+  }
+
+  commentLocations.sort((a, b) => a.start - b.start);
+
+  // Merge overlapping comments
+  const mergedCommentLocations = [];
+  let lastCommentLocation = null;
+  for (const location of commentLocations) {
+    if (lastCommentLocation) {
+      if (location.start >= lastCommentLocation.end) {
+        mergedCommentLocations.push(location);
+        lastCommentLocation = location;
+      } else {
+        lastCommentLocation.end = Math.max(
+          lastCommentLocation.end,
+          location.end,
+        );
+      }
+    } else {
+      mergedCommentLocations.push(location);
+      lastCommentLocation = location;
+    }
+  }
+  return mergedCommentLocations;
+}

src/parseImports.js

@@ -1,3 +1,5 @@
+import { getCommentLocations } from "./parseComments.js";
+
 /**
  * @typedef {Object} ImportLocation
  * @property {number} start
@@ -7,14 +9,14 @@
 
 /**
  * @param {RegExpMatchArray} match
- * @param {ImportLocation[]} imports
+ * @param {Set<ImportLocation>} imports
  */
 function parseMatch(match, imports) {
   const url = match.groups?.url;
   // @ts-expect-error indices does not exist but all browsers support it
   const start = match.indices.groups?.url[0];
   if (url && start !== undefined) {
-    imports.push({
+    imports.add({
       start,
       length: url.length,
       url,
@@ -28,8 +30,8 @@ function parseMatch(match, imports) {
  * @param {string} scriptSource
  */
 export function parseImports(scriptSource) {
-  /** @type {ImportLocation[]} */
-  const imports = [];
+  /** @type {Set<ImportLocation>} */
+  const imports = new Set();
   const staticImportRegex = /(?:^|;)\s*import[\s\S]+?["'](?<url>.+?)["']/gmd;
   for (const match of scriptSource.matchAll(staticImportRegex)) {
     parseMatch(match, imports);
@@ -38,5 +40,25 @@ export function parseImports(scriptSource) {
   for (const match of scriptSource.matchAll(dynamicImportRegex)) {
     parseMatch(match, imports);
   }
-  return imports;
+
+  const commentLocation = getCommentLocations(scriptSource);
+
+  /** @type {ImportLocation[]} */
+  const overlappingImports = [];
+  for (const importLocation of imports) {
+    for (const comment of commentLocation) {
+      const importStart = importLocation.start;
+      const importEnd = importLocation.start + importLocation.length;
+      // If import overlaps with the comment
+      if (importEnd > comment.start && importStart < comment.end) {
+        overlappingImports.push(importLocation);
+      }
+    }
+  }
+
+  for (const overlapping of overlappingImports) {
+    imports.delete(overlapping);
+  }
+
+  return Array.from(imports);
 }

test/unit/src/parseComments.test.js

@@ -0,0 +1,167 @@
+import { assertEquals } from "https://deno.land/[email protected]/testing/asserts.ts";
+import { getCommentLocations } from "../../../src/parseComments.js";
+
+Deno.test({
+  name: "single line comment",
+  fn() {
+    const source = `// comment`;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 0, end: 10 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "line comment after non comment",
+  fn() {
+    const source = `
+      not a comment // comment
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 21, end: 31 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "line comment in between non comments",
+  fn() {
+    const source = `
+      not a comment
+      not a comment // comment
+      not a comment
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 41, end: 51 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "multiple line comments",
+  fn() {
+    const source = `
+      // comment
+      not a comment
+      not a comment // comment
+      not a comment // comment
+      not a comment
+      not a comment // comment
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 7, end: 17 },
+      { start: 58, end: 68 },
+      { start: 89, end: 99 },
+      { start: 140, end: 150 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "block comment",
+  fn() {
+    const source = `/* comment */`;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 0, end: 13 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "multi line block comment",
+  fn() {
+    const source = `
+      /*
+       comment
+       */
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 7, end: 34 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "jsdoc style comment",
+  fn() {
+    const source = `
+      /**
+       * @fileoverview test
+       */
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 7, end: 48 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "line comment inside block comment",
+  fn() {
+    const source = `
+      /*
+      // comment
+      */
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 7, end: 35 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "block comment between non comments",
+  fn() {
+    const source = `
+      not a comment
+      /* comment */
+      not a comment
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 27, end: 40 },
+    ]);
+  },
+});
+
+Deno.test({
+  name: "block comment inside line comment",
+  fn() {
+    const source = `
+      // comment /* comment */
+      not a comment
+    `;
+
+    const result = getCommentLocations(source);
+
+    assertEquals(result, [
+      { start: 7, end: 31 },
+    ]);
+  },
+});

test/unit/src/parseImports.test.js

@@ -133,3 +133,59 @@ Deno.test("Dynamic", () => {
     },
   ]);
 });
+
+Deno.test({
+  name: "Doesn't import inside comments",
+  fn() {
+    const scriptSources = [
+      `
+		// import './script.js';
+	  `,
+      `
+		// import "./script.js";
+	  `,
+      `
+		// import {named} from "./script.js";
+	  `,
+      `
+		/* import './script.js'; */
+	  `,
+      `
+		/*
+		 * import "./script.js";
+		 */
+	  `,
+      `
+    // import("./script.js")
+    `,
+      `
+    // ;import "./script.js"
+    `,
+      `
+    /*
+    import "./script.js";
+    */
+    `,
+      `
+    /*
+    import("./script.js")
+    */
+    `,
+      `
+    /*
+     * import("./script.js")
+    */
+    `,
+    ];
+
+    for (const source of scriptSources) {
+      const imports = parseImports(source);
+
+      assertEquals(
+        imports,
+        [],
+        `The following should not have imports: ${source}`,
+      );
+    }
+  },
+});