Fix empty wildcard match on exports (#2264)

Author: lauckhart

internal/modulespecifiers/specifiers.go

@@ -1207,23 +1207,23 @@ func tryGetModuleNameFromExportsOrImports(
 		case MatchingModePattern:
 			leadingSlice, trailingSlice, _ := strings.Cut(pathOrPattern, "*")
 			caseSensitive := host.UseCaseSensitiveFileNames()
-			if canTryTsExtension && stringutil.HasPrefix(targetFilePath, leadingSlice, caseSensitive) && stringutil.HasSuffix(targetFilePath, trailingSlice, caseSensitive) {
+			if canTryTsExtension && stringutil.HasPrefixAndSuffixWithoutOverlap(targetFilePath, leadingSlice, trailingSlice, caseSensitive) {
 				starReplacement := targetFilePath[len(leadingSlice) : len(targetFilePath)-len(trailingSlice)]
 				return replaceFirstStar(packageName, starReplacement)
 			}
-			if len(extensionSwappedTarget) > 0 && stringutil.HasPrefix(extensionSwappedTarget, leadingSlice, caseSensitive) && stringutil.HasSuffix(extensionSwappedTarget, trailingSlice, caseSensitive) {
+			if len(extensionSwappedTarget) > 0 && stringutil.HasPrefixAndSuffixWithoutOverlap(extensionSwappedTarget, leadingSlice, trailingSlice, caseSensitive) {
 				starReplacement := extensionSwappedTarget[len(leadingSlice) : len(extensionSwappedTarget)-len(trailingSlice)]
 				return replaceFirstStar(packageName, starReplacement)
 			}
-			if !canTryTsExtension && stringutil.HasPrefix(targetFilePath, leadingSlice, caseSensitive) && stringutil.HasSuffix(targetFilePath, trailingSlice, caseSensitive) {
+			if !canTryTsExtension && stringutil.HasPrefixAndSuffixWithoutOverlap(targetFilePath, leadingSlice, trailingSlice, caseSensitive) {
 				starReplacement := targetFilePath[len(leadingSlice) : len(targetFilePath)-len(trailingSlice)]
 				return replaceFirstStar(packageName, starReplacement)
 			}
-			if len(outputFile) > 0 && stringutil.HasPrefix(outputFile, leadingSlice, caseSensitive) && stringutil.HasSuffix(outputFile, trailingSlice, caseSensitive) {
+			if len(outputFile) > 0 && stringutil.HasPrefixAndSuffixWithoutOverlap(outputFile, leadingSlice, trailingSlice, caseSensitive) {
 				starReplacement := outputFile[len(leadingSlice) : len(outputFile)-len(trailingSlice)]
 				return replaceFirstStar(packageName, starReplacement)
 			}
-			if len(declarationFile) > 0 && stringutil.HasPrefix(declarationFile, leadingSlice, caseSensitive) && stringutil.HasSuffix(declarationFile, trailingSlice, caseSensitive) {
+			if len(declarationFile) > 0 && stringutil.HasPrefixAndSuffixWithoutOverlap(declarationFile, leadingSlice, trailingSlice, caseSensitive) {
 				starReplacement := declarationFile[len(leadingSlice) : len(declarationFile)-len(trailingSlice)]
 				substituted := replaceFirstStar(packageName, starReplacement)
 				jsExtension := tryGetJSExtensionForFile(declarationFile, options)

internal/modulespecifiers/specifiers_test.go

@@ -256,3 +256,53 @@ func TestContainsIgnoredPath(t *testing.T) {
 		})
 	}
 }
+
+func TestTryGetModuleNameFromExportsOrImports(t *testing.T) {
+	t.Parallel()
+	t.Run("with exports pattern", func(t *testing.T) {
+		t.Parallel()
+
+		tests := []struct {
+			name           string
+			targetFilePath string
+			expected       string
+		}{
+			{
+				name:           "match",
+				targetFilePath: "/pkg/src/things/thing1/index.ts",
+				expected:       "./src/things/thing1",
+			},
+			{
+				name:           "mismatch with matching leading and trailing strings",
+				targetFilePath: "/pkg/src/things/index.ts",
+				expected:       "",
+			},
+		}
+
+		for _, tt := range tests {
+			t.Run(tt.name, func(t *testing.T) {
+				t.Parallel()
+				result := tryGetModuleNameFromExportsOrImports(
+					&core.CompilerOptions{},
+					&mockModuleSpecifierGenerationHost{},
+					tt.targetFilePath,
+					"/pkg",
+					"./src/things/*",
+					packagejson.ExportsOrImports{
+						JSONValue: packagejson.JSONValue{
+							Type:  packagejson.JSONValueTypeString,
+							Value: "./src/things/*/index.js",
+						},
+					},
+					[]string{},
+					MatchingModePattern,
+					false,
+					false,
+				)
+				if result != tt.expected {
+					t.Errorf("tryGetModuleNameFromExportsOrImports(targetFilePath = %q) = %v, expected %v", tt.targetFilePath, result, tt.expected)
+				}
+			})
+		}
+	})
+}

internal/stringutil/compare.go

@@ -91,6 +91,14 @@ func HasSuffix(s string, suffix string, caseSensitive bool) bool {
 	return strings.EqualFold(s[len(s)-len(suffix):], suffix)
 }
 
+func HasPrefixAndSuffixWithoutOverlap(s string, prefix string, suffix string, caseSensitive bool) bool {
+	if len(prefix)+len(suffix) > len(s) {
+		return false
+	}
+
+	return HasPrefix(s, prefix, caseSensitive) && HasSuffix(s, suffix, caseSensitive)
+}
+
 func CompareStringsCaseInsensitiveThenSensitive(a, b string) Comparison {
 	cmp := CompareStringsCaseInsensitive(a, b)
 	if cmp != ComparisonEqual {