fix: improve file resolution (#601)

packages/cspell-lib/src/Settings/CSpellSettingsServer.ts

@@ -14,7 +14,7 @@ import { normalizePathForDictDefs } from './DictionarySettings';
 import * as util from '../util/util';
 import ConfigStore from 'configstore';
 import minimatch from 'minimatch';
-import resolveFrom from 'resolve-from';
+import { resolveFile } from '../util/resolveFile';
 
 const currentSettingsFileVersion = '0.1';
 
@@ -281,33 +281,13 @@ function applyPatterns(
     return [...flatten(patternList)];
 }
 
-const testNodeModules = /^node_modules\//;
-
 function resolveFilename(filename: string, relativeTo: string): ImportFileRef {
-    if (testNodeModules.test(filename)) {
-        filename = filename.replace(testNodeModules, '');
-    }
-
-    const try1 = tryResolve(filename, relativeTo);
-    if (!try1.error || filename.startsWith('.')) {
-        return try1;
-    }
-
-    // Try to resolve as a relative module
-    const normalizedFilename = './' + (path.sep === '/' ? filename : filename.split(path.sep).join('/'));
-    return tryResolve(normalizedFilename, relativeTo);
-}
+    const r = resolveFile(filename, relativeTo);
 
-function tryResolve(filename: string, relativeTo: string): ImportFileRef {
-    try {
-        return { filename: resolveFrom(relativeTo, filename) };
-    } catch (error) {
-        // Failed to resolve a relative module request
-        return {
-            filename: filename,
-            error: new Error(`Failed to resolve file: "${filename}"`),
-        };
-    }
+    return {
+        filename: r.filename,
+        error: r.found ? undefined : new Error(`Failed to resolve file: "${filename}"`),
+    };
 }
 
 export function getGlobalSettings(): CSpellSettings {

packages/cspell-lib/src/util/resolveFile.test.ts

@@ -0,0 +1,55 @@
+import { resolveFile } from './resolveFile';
+import * as path from 'path';
+import { parse } from 'comment-json';
+import * as fs from 'fs';
+
+interface Config {
+    import: string[];
+}
+
+const config: Config = parse(
+    fs.readFileSync(path.join(__dirname, '..', '..', 'config', 'cspell-default.json'), 'utf-8')
+);
+
+const ext = path.extname(__filename);
+
+describe('Validate resolveFile', () => {
+    interface ResolveFileTest {
+        filename: string;
+        relativeTo: string;
+        expected: string;
+        found: boolean;
+    }
+    test.each`
+        filename                                | relativeTo   | expected                                              | found
+        ${__filename}                           | ${__dirname} | ${__filename}                                         | ${true}
+        ${path.relative(__dirname, __filename)} | ${__dirname} | ${__filename}                                         | ${true}
+        ${'cspell-dict-cpp/cspell-ext.json'}    | ${__dirname} | ${require.resolve('cspell-dict-cpp/cspell-ext.json')} | ${true}
+        ${'cspell-ext.json'}                    | ${__dirname} | ${'cspell-ext.json'}                                  | ${false}
+        ${`./resolveFile${ext}`}                | ${__dirname} | ${require.resolve('./resolveFile')}                   | ${true}
+        ${`resolveFile${ext}`}                  | ${__dirname} | ${require.resolve('./resolveFile')}                   | ${true}
+        ${'lerna'}                              | ${__dirname} | ${require.resolve('lerna')}                           | ${true}
+    `('resolveFile "$filename" rel "$relativeTo"', validateResolveFile);
+
+    test.each(
+        config.import
+            .concat(config.import.map((f) => f.replace('node_modules/', '')))
+            .map((f) => ({
+                filename: f,
+                relativeTo: __dirname,
+                expected: require.resolve(f.replace('node_modules/', '')),
+                found: true,
+            }))
+            .map(({ filename, relativeTo, expected, found }) => [filename, relativeTo, expected, found])
+    )('resolveFile "%s" rel "%s"', validateResolveArgs);
+
+    function validateResolveFile({ filename, relativeTo, expected, found }: ResolveFileTest) {
+        validateResolveArgs(filename, relativeTo, expected, found);
+    }
+
+    function validateResolveArgs(filename: string, relativeTo: string, expected: string, found: boolean) {
+        const r = resolveFile(filename, relativeTo);
+        expect(r.filename).toBe(expected);
+        expect(r.found).toBe(found);
+    }
+});

packages/cspell-lib/src/util/resolveFile.ts

@@ -0,0 +1,40 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import resolveFrom from 'resolve-from';
+
+export interface ResolveFileResult {
+    filename: string;
+    found: boolean;
+}
+
+const testNodeModules = /^node_modules\//;
+
+export function resolveFile(filename: string, relativeTo: string): ResolveFileResult {
+    const methodResolveFrom = (filename: string) => tryResolveFrom(filename, relativeTo);
+    const steps: { filename: string; fn: (f: string) => ResolveFileResult }[] = [
+        { filename: path.resolve(relativeTo, filename), fn: tryResolveExists },
+        { filename: path.resolve(filename), fn: tryResolveExists },
+        { filename: filename, fn: methodResolveFrom },
+        { filename: filename.replace(testNodeModules, ''), fn: methodResolveFrom },
+        { filename: './' + (path.sep === '/' ? filename : filename.split(path.sep).join('/')), fn: methodResolveFrom },
+    ];
+
+    for (const step of steps) {
+        const r = step.fn(step.filename);
+        if (r.found) return r;
+    }
+    return { filename, found: false };
+}
+
+function tryResolveExists(filename: string): ResolveFileResult {
+    return { filename, found: fs.existsSync(filename) };
+}
+
+function tryResolveFrom(filename: string, relativeTo: string): ResolveFileResult {
+    try {
+        return { filename: resolveFrom(relativeTo, filename), found: true };
+    } catch (error) {
+        // Failed to resolve a relative module request
+        return { filename: filename, found: false };
+    }
+}