feat: link with input HTML map when no importmap.json is present

docs.md

@@ -37,7 +37,7 @@ In some cases there may be ambiguity. For instance, you may want to link the NPM
 If no modules are given, all "imports" in the initial map are relinked.
 
 ### Options
-* `-m, --map` _<file>_                File containing initial import map (default: importmap.json)
+* `-m, --map` _<file>_                File containing initial import map (defaults to importmap.json, or the input HTML if linking) 
 * `-o, --output` _<file>_             File to inject the final import map into (default: --map / importmap.json) 
 * `-e, --env` <[environments](#environments)>        Comma-separated environment condition overrides 
 * `-r, --resolution` <[resolutions](#resolutions)>  Comma-separated dependency resolution overrides 
@@ -65,7 +65,7 @@ jspm link ./src/cli.js
 Link an HTML file and update its import map including preload and integrity tags
 
 ```
-jspm link --map index.html --integrity --preload dynamic
+jspm link --map index.html --integrity --preload
 ```
 ## install
 
@@ -79,7 +79,7 @@ Installs packages into an import map, along with all of the dependencies that ar
 If no packages are provided, all "imports" in the initial map are reinstalled.
 
 ### Options
-* `-m, --map` _<file>_                File containing initial import map (default: importmap.json)
+* `-m, --map` _<file>_                File containing initial import map (defaults to importmap.json, or the input HTML if linking) 
 * `-o, --output` _<file>_             File to inject the final import map into (default: --map / importmap.json) 
 * `-e, --env` <[environments](#environments)>        Comma-separated environment condition overrides 
 * `-r, --resolution` <[resolutions](#resolutions)>  Comma-separated dependency resolution overrides 
@@ -129,7 +129,7 @@ jspm uninstall [flags] [...packages]
 Uninstalls packages from an import map. The given packages must be valid package specifiers, such as `npm:[email protected]`, `denoland:oak` or `lit`, and must be present in the initial import map.
 
 ### Options
-* `-m, --map` _<file>_                File containing initial import map (default: importmap.json)
+* `-m, --map` _<file>_                File containing initial import map (defaults to importmap.json, or the input HTML if linking) 
 * `-o, --output` _<file>_             File to inject the final import map into (default: --map / importmap.json) 
 * `-e, --env` <[environments](#environments)>        Comma-separated environment condition overrides 
 * `-r, --resolution` <[resolutions](#resolutions)>  Comma-separated dependency resolution overrides 
@@ -161,7 +161,7 @@ jspm update [flags] [...packages]
 Updates packages in an import map to the latest versions that are compatible with the local `package.json`. The given packages must be valid package specifiers, such as `npm:[email protected]`, `denoland:oak` or `lit`, and must be present in the initial import map.
 
 ### Options
-* `-m, --map` _<file>_                File containing initial import map (default: importmap.json)
+* `-m, --map` _<file>_                File containing initial import map (defaults to importmap.json, or the input HTML if linking) 
 * `-o, --output` _<file>_             File to inject the final import map into (default: --map / importmap.json) 
 * `-e, --env` <[environments](#environments)>        Comma-separated environment condition overrides 
 * `-r, --resolution` <[resolutions](#resolutions)>  Comma-separated dependency resolution overrides 

src/cli.ts

@@ -30,8 +30,8 @@ export const cli = cac(c.yellow("jspm"));
 type opt = [string, string, any];
 const mapOpt: opt = [
   "-m, --map <file>",
-  "File containing initial import map",
-  { default: "importmap.json" },
+  "File containing initial import map (defaults to importmap.json, or the input HTML if linking)",
+  {},
 ];
 const envOpt: opt = [
   "-e, --env <environments>",
@@ -144,7 +144,7 @@ cli
     (
       name
     ) => `Link an HTML file and update its import map including preload and integrity tags
-  $ ${name} link --map index.html --integrity --preload dynamic
+  $ ${name} link --map index.html --integrity --preload
 `
   )
   .usage(

src/link.ts

@@ -1,4 +1,5 @@
 import * as fs from "node:fs/promises";
+import { extname } from "node:path";
 import { pathToFileURL } from "url";
 import c from "picocolors";
 import { type Generator } from "@jspm/generator";
@@ -9,6 +10,7 @@ import {
   getInput,
   getInputPath,
   getOutputPath,
+  isJsExtension,
   startSpinner,
   stopSpinner,
   writeOutput,
@@ -21,8 +23,10 @@ export default async function link(modules: string[], flags: Flags) {
   log(`Linking modules: ${modules.join(", ")}`);
   log(`Flags: ${JSON.stringify(flags)}`);
 
+  const fallbackMap = !modules[0] || isJsExtension(extname(modules[0])) ? undefined : modules[0];
+
   const env = await getEnv(flags);
-  const inputMapPath = getInputPath(flags);
+  const inputMapPath = getInputPath(flags, fallbackMap);
   const outputMapPath = getOutputPath(flags);
   const generator = await getGenerator(flags);
 
@@ -36,7 +40,7 @@ export default async function link(modules: string[], flags: Flags) {
   // The input map is either from a JSON file or extracted from an HTML file.
   // In the latter case we want to trace any inline modules from the HTML file
   // as well, since they may have imports that are not in the import map yet:
-  const input = await getInput(flags);
+  const input = await getInput(flags, fallbackMap);
   const pins = inlinePins.concat(resolvedModules.map((p) => p.target));
   let allPins = pins;
   if (input) {

src/utils.ts

@@ -1,4 +1,5 @@
 import fs from "node:fs/promises";
+import { accessSync } from "node:fs";
 import path from "node:path";
 import { pathToFileURL } from "node:url";
 import { Generator, analyzeHtml } from "@jspm/generator";
@@ -8,7 +9,20 @@ import { withType } from "./logger";
 import type { Flags, IImportMapJspm } from "./types";
 
 // Default import map to use if none is provided:
-const defaultInputPath = "./importmap.json";
+const defaultMapPath = "importmap.json";
+
+export function isJsExtension(ext) {
+  return (
+    ext === ".js" ||
+    ext === ".mjs" ||
+    ext === ".cjs" ||
+    ext === ".ts" ||
+    ext === ".mts" ||
+    ext === ".cts" ||
+    ext === ".jsx" ||
+    ext === ".tsx"
+  );
+}
 
 // Default HTML for import map injection:
 const defaultHtmlTemplate = `<!DOCTYPE html>
@@ -105,7 +119,7 @@ async function writeHtmlOutput(
     );
 
   const mapFileRel = path.relative(process.cwd(), mapFile);
-  if (!(await exists(mapFile))) {
+  if (!exists(mapFile)) {
     !silent &&
       console.warn(
         `${c.cyan(
@@ -213,11 +227,14 @@ export async function getGenerator(
   });
 }
 
-export async function getInput(flags: Flags): Promise<string | undefined> {
-  const mapFile = getInputPath(flags);
-  if (!(await exists(mapFile))) return undefined;
-  if (!(await canRead(mapFile))) {
-    if (mapFile === defaultInputPath) return undefined;
+export async function getInput(
+  flags: Flags,
+  fallbackDefaultMap = defaultMapPath
+): Promise<string | undefined> {
+  const mapFile = getInputPath(flags, fallbackDefaultMap);
+  if (!exists(mapFile)) return undefined;
+  if (!canRead(mapFile)) {
+    if (mapFile === defaultMapPath) return undefined;
     else
       throw new JspmError(`JSPM does not have permission to read ${mapFile}.`);
   }
@@ -249,14 +266,20 @@ async function getInputMap(flags: Flags): Promise<IImportMapJspm> {
   return (inputMap || {}) as IImportMapJspm;
 }
 
-export function getInputPath(flags: Flags): string {
-  return path.resolve(process.cwd(), flags?.map || defaultInputPath);
+export function getInputPath(
+  flags: Flags,
+  fallbackDefaultMap = defaultMapPath
+): string {
+  return path.resolve(
+    process.cwd(),
+    flags?.map || (exists(defaultMapPath) ? defaultMapPath : fallbackDefaultMap)
+  );
 }
 
 export function getOutputPath(flags: Flags): string | undefined {
   return path.resolve(
     process.cwd(),
-    flags.output || flags.map || defaultInputPath
+    flags.output || flags.map || defaultMapPath
   );
 }
 
@@ -409,28 +432,28 @@ export function stopSpinner() {
   spinner.stop();
 }
 
-export async function exists(file: string) {
+export function exists(file: string) {
   try {
-    await fs.access(file);
+    accessSync(file);
     return true;
   } catch (e) {
     return false;
   }
 }
 
-async function canRead(file: string) {
+function canRead(file: string) {
   try {
-    await fs.access(file, (fs.constants || fs).R_OK);
+    accessSync(file, (fs.constants || fs).R_OK);
     return true;
   } catch (e) {
     return false;
   }
 }
 
-async function canWrite(file: string) {
+function canWrite(file: string) {
   try {
-    if (!(await exists(file))) return true;
-    await fs.access(file, (fs.constants || fs).W_OK);
+    if (!exists(file)) return true;
+    accessSync(file, (fs.constants || fs).W_OK);
     return true;
   } catch (e) {
     return false;

test/fixtures/index.html

@@ -15,3 +15,4 @@ <h1>Test</h1>
   }
 }
 </script>
+<script type="module" src="app.js"></script>

test/link.test.ts

@@ -139,6 +139,18 @@ const scenarios: Scenario[] = [
       assert(!map.imports?.["react-dom"]);
     },
   },
+
+  // Support the HTML as being the import map when there is no importmap.json:
+  {
+    files: new Map([...htmlFile, ['app.js', 'import "react"']]),
+    commands: ["jspm link index.html -o index.html --integrity"],
+    validationFn: async (files: Map<string, string>) => {
+      const source = files.get('index.html');
+      assert(source.includes('"integrity"'));
+      assert(source.includes('"./app.js": "sha384-f+bWmpnsmFol2CAkqy/ALGgZsi/mIaBIIhbvFLVuQzt0LNz96zLSDcz1fnF2K22q"'));
+      assert(source.includes('"https://ga.jspm.io/npm:[email protected]/dev.index.js": "sha384-eSJrEMXot96AKVLYz8C1nY3CpLMuBMHIAiYhs7vfM09SQo+5X+1w6t3Ldpnw+VWU"'))
+    },
+  },
 ];
 
 await runScenarios(scenarios);