esbuild import path resolution issue with angular v17 for modules outsides the workspace

git clone https://github.com/thomaspeugeot/ngimportissue.git

Situation

A workspace has been created with angular version 17.

% ng version
...
Angular CLI: 17.0.3

the workspace has been created with the following config

ng new ng --defaults=true --minimal=true --no-standalone --routing --ssr=false

The issue arises when ng tries to compiles modules outsides the workspace.

As seen in ng/src/app/app.module.ts, the application imports some modules that are outside the workspace. One of them is GongModule.

...
import { GongModule } from 'gong'


@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    ...
    GongModule,

As seen in vendor/github.com/fullstack-lang/gong/ng/projects/gong/src/lib/gong.module.ts, GongModule itself imports angular modules

import { NgModule } from '@angular/core';

@NgModule({
	declarations: [
	],
	imports: [
		CommonModule,

        ...
...

Angular cannot build the application

 % ng build
⠋ Building...✘ [ERROR] Could not resolve "@angular/common/http"

    ../vendor/github.com/fullstack-lang/gong/ng/projects/gong/src/lib/commitnbfromback.service.ts:2:27:
      2 │ import { HttpParams } from '@angular/common/http';
        ╵                            ~~~~~~~~~~~~~~~~~~~~~~
...

Preliminary analysis

This is new with ng 17

This problem did not occur with ng v16

This is an issue related to the import path

going verbose and having a trace in ng/build_trace.txt, one better understands what's wrong

% ng build --verbose > build_trace.txt 2>&1

ng/build_trace.txt

Searching for "@angular/common/http" in "node_modules" directories starting from "/private/tmp/ngimportissue/vendor/github.com/fullstack-lang/gongdoc/ng/projects/gongdoc/src/lib"
    Matching "@angular/common/http" against "paths" in "/private/tmp/ngimportissue/ng/tsconfig.app.json"
      Using "/private/tmp/ngimportissue/ng" as "baseURL"
      Found a fuzzy match for "*" in "paths"
      Attempting to load "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http" as a file
        Checking for file "http"
        Checking for file "http.mjs"
        Checking for file "http.js"
        Checking for file "http.ts"
        Checking for file "http.tsx"
        Failed to find file "http"
      Attempting to load "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http" as a directory
        Read 2 entries for directory "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http"
        No "browser" map found in directory "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http"
        Failed to find file "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http/index.mjs"
        Failed to find file "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http/index.js"
        Failed to find file "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http/index.ts"
        Failed to find file "/private/tmp/ngimportissue/ng/node_modules/@angular/common/http/index.tsx"
    Parsed package name "@angular/common" and package subpath "./http"

✘ [ERROR] Could not resolve "@angular/common/http"

It seems the builder is mislead by the the import path. It does not search the esm2022 or fesm2022 where the index file is present. Indeed ng/node_modules/@angular/common/esm2022/http/http.mjs is present (for information, this file is present but not in the git repo also, you need to perfom npm i to have it present).

The import path in ng/tsconfig.json that worked with ng v16 is configured to work with import path outside the workspace.

    "paths": {
      "*": [
        "./node_modules/*"
      ],

It does not work with ng 17.

There is a Workaround

If one configures the project as a browser instead of application, the compilation works. It is this configuration that is created when one migrates the projects from ng 16 to ng 17.

Below is the diff for ng/angular.json

--- a/ng/angular.json
+++ b/ng/angular.json
@@ -5,7 +5,7 @@
     "ng": {
       "architect": {
         "build": {
-          "builder": "@angular-devkit/build-angular:application",
+          "builder": "@angular-devkit/build-angular:browser",
           "configurations": {
             "development": {
               "extractLicenses": false,
@@ -34,7 +34,7 @@
               "src/favicon.ico",
               "src/assets"
             ],
-            "browser": "src/main.ts",
+            "main": "src/main.ts",
             "index": "src/index.html",
:...skipping...
diff --git a/ng/angular.json b/ng/angular.json
index 288f403..f4e5a7c 100644
--- a/ng/angular.json
+++ b/ng/angular.json
@@ -5,7 +5,7 @@
     "ng": {
       "architect": {
         "build": {
-          "builder": "@angular-devkit/build-angular:application",
+          "builder": "@angular-devkit/build-angular:browser",
           "configurations": {
             "development": {
               "extractLicenses": false,
@@ -34,7 +34,7 @@
               "src/favicon.ico",
               "src/assets"
             ],
-            "browser": "src/main.ts",
+            "main": "src/main.ts",
             "index": "src/index.html",
             "outputPath": "dist/ng",
             "polyfills": [

since https://angular.io/guide/esbuild https://angular.io/guide/esbuild#using-the-application-builder states that this is esbuild that performs the compilation, I surmises this is an issue related to esbuild.