Simplify logic to determine installation help

Author: lovell

docs/install.md

@@ -118,11 +118,11 @@ When building your deployment package on a machine that differs from the target
 you will need to install either `@img/sharp-linux-x64` or `@img/sharp-linux-arm64` package.
 
 ```sh
-npm install --os=linux --cpu=x64
+npm install --os=linux --cpu=x64 sharp
 ```
 
 ```sh
-npm install --os=linux --cpu=arm64
+npm install --os=linux --cpu=arm64 sharp
 ```
 
 When using npm 9 or earlier, this can be achieved using the following:

lib/sharp.js

@@ -9,62 +9,71 @@ const { familySync, versionSync } = require('detect-libc');
 
 const { runtimePlatformArch, prebuiltPlatforms, minimumLibvipsVersion } = require('./libvips');
 const runtimePlatform = runtimePlatformArch();
-const [isLinux, isMacOs, isWindows] = ['linux', 'darwin', 'win32'].map(os => runtimePlatform.startsWith(os));
 
-/* istanbul ignore next */
-try {
-  // Check for local build
-  module.exports = require(`../src/build/Release/sharp-${runtimePlatform}.node`);
-} catch (errLocal) {
+const paths = [
+  `../src/build/Release/sharp-${runtimePlatform}.node`,
+  `@img/sharp-${runtimePlatform}/sharp.node`
+];
+
+const errors = [];
+for (const path of paths) {
   try {
-    // Check for runtime package
-    module.exports = require(`@img/sharp-${runtimePlatform}/sharp.node`);
-  } catch (errPackage) {
-    const help = ['Could not load the "sharp" module at runtime'];
-    if (errLocal.code !== 'MODULE_NOT_FOUND') {
-      help.push(`${errLocal.code}: ${errLocal.message}`);
-    }
-    if (errPackage.code !== 'MODULE_NOT_FOUND') {
-      help.push(`${errPackage.code}: ${errPackage.message}`);
-    }
-    help.push('Possible solutions:');
-    // Common error messages
-    if (prebuiltPlatforms.includes(runtimePlatform)) {
-      const [os, cpu] = runtimePlatform.split('-');
-      help.push('- Add an explicit dependency for the runtime platform:');
-      help.push(`    npm install --os=${os} --cpu=${cpu} sharp`);
-      help.push('  or');
-      help.push(`    npm install --force @img/sharp-${runtimePlatform}`);
-    } else {
-      help.push(`- The ${runtimePlatform} platform requires manual installation of libvips >= ${minimumLibvipsVersion}`);
-    }
-    if (isLinux && /symbol not found/i.test(errPackage)) {
-      try {
-        const { engines } = require(`@img/sharp-libvips-${runtimePlatform}/package`);
-        const libcFound = `${familySync()} ${versionSync()}`;
-        const libcRequires = `${engines.musl ? 'musl' : 'glibc'} ${engines.musl || engines.glibc}`;
-        help.push('- Update your OS:');
-        help.push(`    Found ${libcFound}`);
-        help.push(`    Requires ${libcRequires}`);
-      } catch (errEngines) {}
-    }
-    if (isMacOs && /Incompatible library version/.test(errLocal.message)) {
-      help.push('- Update Homebrew:');
-      help.push('    brew update && brew upgrade vips');
-    }
-    if (errPackage.code === 'ERR_DLOPEN_DISABLED') {
-      help.push('- Run Node.js without using the --no-addons flag');
-    }
-    if (process.versions.pnp) {
-      help.push('- Use a supported yarn linker, either pnpm or node-modules:');
-      help.push('    yarn config set nodeLinker node-modules');
-    }
-    // Link to installation docs
-    if (isWindows && /The specified procedure could not be found/.test(errPackage.message)) {
-      help.push('- Using the canvas package on Windows? See https://sharp.pixelplumbing.com/install#canvas-and-windows');
-    } else {
-      help.push('- Consult the installation documentation: https://sharp.pixelplumbing.com/install');
+    module.exports = require(path);
+    break;
+  } catch (err) {
+    /* istanbul ignore next */
+    errors.push(err);
+  }
+}
+
+/* istanbul ignore next */
+if (!module.exports) {
+  const [isLinux, isMacOs, isWindows] = ['linux', 'darwin', 'win32'].map(os => runtimePlatform.startsWith(os));
+
+  const help = [`Could not load the "sharp" module using the ${runtimePlatform} runtime`];
+  errors.forEach(err => {
+    if (err.code !== 'MODULE_NOT_FOUND') {
+      help.push(`${err.code}: ${err.message}`);
     }
-    throw new Error(help.join('\n'));
+  });
+  const messages = errors.map(err => err.message).join(' ');
+  help.push('Possible solutions:');
+  // Common error messages
+  if (prebuiltPlatforms.includes(runtimePlatform)) {
+    const [os, cpu] = runtimePlatform.split('-');
+    help.push('- Add platform-specific dependencies:');
+    help.push(`    npm install --os=${os} --cpu=${cpu} sharp`);
+    help.push('  or');
+    help.push(`    npm install --force @img/sharp-${runtimePlatform}`);
+  } else {
+    help.push(`- Manually install libvips >= ${minimumLibvipsVersion}`);
+  }
+  if (isLinux && /symbol not found/i.test(messages)) {
+    try {
+      const { engines } = require(`@img/sharp-libvips-${runtimePlatform}/package`);
+      const libcFound = `${familySync()} ${versionSync()}`;
+      const libcRequires = `${engines.musl ? 'musl' : 'glibc'} ${engines.musl || engines.glibc}`;
+      help.push('- Update your OS:');
+      help.push(`    Found ${libcFound}`);
+      help.push(`    Requires ${libcRequires}`);
+    } catch (errEngines) {}
+  }
+  if (isMacOs && /Incompatible library version/.test(messages)) {
+    help.push('- Update Homebrew:');
+    help.push('    brew update && brew upgrade vips');
+  }
+  if (errors.some(err => err.code === 'ERR_DLOPEN_DISABLED')) {
+    help.push('- Run Node.js without using the --no-addons flag');
+  }
+  if (process.versions.pnp) {
+    help.push('- Use a supported yarn linker, either pnpm or node-modules:');
+    help.push('    yarn config set nodeLinker node-modules');
+  }
+  // Link to installation docs
+  if (isWindows && /The specified procedure could not be found/.test(messages)) {
+    help.push('- Using the canvas package on Windows? See https://sharp.pixelplumbing.com/install#canvas-and-windows');
+  } else {
+    help.push('- Consult the installation documentation: https://sharp.pixelplumbing.com/install');
   }
+  throw new Error(help.join('\n'));
 }

package.json

@@ -164,7 +164,7 @@
     "@img/sharp-libvips-win32-ia32": "0.0.3",
     "@img/sharp-libvips-win32-x64": "0.0.3",
     "@types/node": "*",
-    "async": "^3.2.4",
+    "async": "^3.2.5",
     "cc": "^3.0.1",
     "exif-reader": "^2.0.0",
     "extract-zip": "^2.0.1",