suggest enabling missing exports condition (#2163)

Author: evanw

CHANGELOG.md

@@ -96,6 +96,50 @@
       so providing inconsistent metadata for the same path can cause non-determinism.
     ```
 
+* Suggest enabling a missing condition when `exports` map fails ([#2163](https://github.com/evanw/esbuild/issues/2163))
+
+    This release adds another suggestion to the error message that happens when an `exports` map lookup fails if the failure could potentially be fixed by adding a missing condition. Here's what the new error message looks like (which now suggests `--conditions=module` as a possible workaround):
+
+    ```
+    ✘ [ERROR] Could not resolve "@sentry/electron/main"
+
+        index.js:1:24:
+          1 │ import * as Sentry from '@sentry/electron/main'
+            ╵                         ~~~~~~~~~~~~~~~~~~~~~~~
+
+      The path "./main" is not currently exported by package "@sentry/electron":
+
+        node_modules/@sentry/electron/package.json:8:13:
+          8 │   "exports": {
+            ╵              ^
+
+      None of the conditions provided ("require", "module") match any of the currently active conditions
+      ("browser", "default", "import"):
+
+        node_modules/@sentry/electron/package.json:16:14:
+          16 │     "./main": {
+             ╵               ^
+
+      Consider enabling the "module" condition if this package expects it to be enabled. You can use
+      "--conditions=module" to do that.
+
+        node_modules/@sentry/electron/package.json:18:6:
+          18 │       "module": "./esm/main/index.js"
+             ╵       ~~~~~~~~
+
+      Consider using a "require()" call to import this file, which will work because the "require"
+      condition is supported by this package:
+
+        index.js:1:24:
+          1 │ import * as Sentry from '@sentry/electron/main'
+            ╵                         ~~~~~~~~~~~~~~~~~~~~~~~
+
+      You can mark the path "@sentry/electron/main" as external to exclude it from the bundle, which
+      will remove this error.
+    ```
+
+    This particular package had an issue where it was using the Webpack-specific `module` condition without providing a `default` condition. It looks like the intent in this case was to use the standard `import` condition instead. This specific change wasn't suggested here because this error message is for package consumers, not package authors.
+
 ## 0.14.34
 
 Something went wrong with the publishing script for the previous release. Publishing again.

internal/bundler/bundler_packagejson_test.go

@@ -1979,10 +1979,12 @@ func TestPackageJsonExportsNoConditionsMatch(t *testing.T) {
 		expectedScanLog: `Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "." is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("what") match any of the currently active conditions ("browser", "default", "import"):
+Users/user/project/node_modules/pkg1/package.json: NOTE: Consider enabling the "what" condition if this package expects it to be enabled. You can use 'Conditions: []string{"what"}' to do that.
 NOTE: You can mark the path "pkg1" as external to exclude it from the bundle, which will remove this error.
 Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1/foo.js"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "./foo.js" is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("what") match any of the currently active conditions ("browser", "default", "import"):
+Users/user/project/node_modules/pkg1/package.json: NOTE: Consider enabling the "what" condition if this package expects it to be enabled. You can use 'Conditions: []string{"what"}' to do that.
 NOTE: You can mark the path "pkg1/foo.js" as external to exclude it from the bundle, which will remove this error.
 `,
 	})
@@ -2019,12 +2021,12 @@ func TestPackageJsonExportsMustUseRequire(t *testing.T) {
 		expectedScanLog: `Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "." is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("require") match any of the currently active conditions ("browser", "default", "import"):
-Users/user/project/src/entry.js: NOTE: Consider using a "require()" call to import this file:
+Users/user/project/src/entry.js: NOTE: Consider using a "require()" call to import this file, which will work because the "require" condition is supported by this package:
 NOTE: You can mark the path "pkg1" as external to exclude it from the bundle, which will remove this error.
 Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1/foo.js"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "./foo.js" is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("require") match any of the currently active conditions ("browser", "default", "import"):
-Users/user/project/src/entry.js: NOTE: Consider using a "require()" call to import this file:
+Users/user/project/src/entry.js: NOTE: Consider using a "require()" call to import this file, which will work because the "require" condition is supported by this package:
 NOTE: You can mark the path "pkg1/foo.js" as external to exclude it from the bundle, which will remove this error.
 `,
 	})
@@ -2061,12 +2063,12 @@ func TestPackageJsonExportsMustUseImport(t *testing.T) {
 		expectedScanLog: `Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "." is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("import") match any of the currently active conditions ("browser", "default", "require"):
-Users/user/project/src/entry.js: NOTE: Consider using an "import" statement to import this file:
+Users/user/project/src/entry.js: NOTE: Consider using an "import" statement to import this file, which will work because the "import" condition is supported by this package:
 NOTE: You can mark the path "pkg1" as external to exclude it from the bundle, which will remove this error. You can also surround this "require" call with a try/catch block to handle this failure at run-time instead of bundle-time.
 Users/user/project/src/entry.js: ERROR: Could not resolve "pkg1/foo.js"
 Users/user/project/node_modules/pkg1/package.json: NOTE: The path "./foo.js" is not currently exported by package "pkg1":
 Users/user/project/node_modules/pkg1/package.json: NOTE: None of the conditions provided ("import") match any of the currently active conditions ("browser", "default", "require"):
-Users/user/project/src/entry.js: NOTE: Consider using an "import" statement to import this file:
+Users/user/project/src/entry.js: NOTE: Consider using an "import" statement to import this file, which will work because the "import" condition is supported by this package:
 NOTE: You can mark the path "pkg1/foo.js" as external to exclude it from the bundle, which will remove this error. You can also surround this "require" call with a try/catch block to handle this failure at run-time instead of bundle-time.
 `,
 	})

internal/resolver/package_json.go

@@ -701,8 +701,9 @@ func (status pjStatus) isUndefined() bool {
 
 type pjDebug struct {
 	// If the status is "pjStatusUndefinedNoConditionsMatch", this is the set of
-	// conditions that didn't match. This information is used for error messages.
-	unmatchedConditions []string
+	// conditions that didn't match, in the order that they were found in the file.
+	// This information is used for error messages.
+	unmatchedConditions []logger.Span
 
 	// This is the range of the token to use for error messages
 	token logger.Range
@@ -1056,9 +1057,9 @@ func (r resolverQuery) esmPackageTargetResolve(
 				// More information: https://github.com/evanw/esbuild/issues/1484
 				target = lastMapEntry.value
 			}
-			keys := make([]string, len(target.mapData))
+			keys := make([]logger.Span, len(target.mapData))
 			for i, p := range target.mapData {
-				keys[i] = p.key
+				keys[i] = logger.Span{Text: p.key, Range: p.keyRange}
 			}
 			return "", pjStatusUndefinedNoConditionsMatch, pjDebug{
 				token:               target.firstToken,

internal/resolver/resolver.go

@@ -2052,25 +2052,61 @@ func (r resolverQuery) finalizeImportsExportsResult(
 			}
 			return strings.Join(quoted, ", ")
 		}
+
 		keys := make([]string, 0, len(conditions))
 		for key := range conditions {
 			keys = append(keys, key)
 		}
 		sort.Strings(keys)
+
+		unmatchedConditions := make([]string, len(debug.unmatchedConditions))
+		for i, key := range debug.unmatchedConditions {
+			unmatchedConditions[i] = key.Text
+		}
+
 		r.debugMeta.notes = []logger.MsgData{
 			tracker.MsgData(importExportMap.root.firstToken,
 				fmt.Sprintf("The path %q is not currently exported by package %q:",
 					esmPackageSubpath, esmPackageName)),
+
 			tracker.MsgData(debug.token,
 				fmt.Sprintf("None of the conditions provided (%s) match any of the currently active conditions (%s):",
-					prettyPrintConditions(debug.unmatchedConditions),
+					prettyPrintConditions(unmatchedConditions),
 					prettyPrintConditions(keys),
-				))}
+				)),
+		}
+
+		didSuggestEnablingCondition := false
 		for _, key := range debug.unmatchedConditions {
-			if key == "import" && (r.kind == ast.ImportRequire || r.kind == ast.ImportRequireResolve) {
-				r.debugMeta.suggestionMessage = "Consider using an \"import\" statement to import this file:"
-			} else if key == "require" && (r.kind == ast.ImportStmt || r.kind == ast.ImportDynamic) {
-				r.debugMeta.suggestionMessage = "Consider using a \"require()\" call to import this file:"
+			switch key.Text {
+			case "import":
+				if r.kind == ast.ImportRequire || r.kind == ast.ImportRequireResolve {
+					r.debugMeta.suggestionMessage = "Consider using an \"import\" statement to import this file, " +
+						"which will work because the \"import\" condition is supported by this package:"
+				}
+
+			case "require":
+				if r.kind == ast.ImportStmt || r.kind == ast.ImportDynamic {
+					r.debugMeta.suggestionMessage = "Consider using a \"require()\" call to import this file, " +
+						"which will work because the \"require\" condition is supported by this package:"
+				}
+
+			default:
+				if !didSuggestEnablingCondition {
+					var how string
+					switch logger.API {
+					case logger.CLIAPI:
+						how = fmt.Sprintf("%q", "--conditions="+key.Text)
+					case logger.JSAPI:
+						how = fmt.Sprintf("\"conditions: ['%s']\"", key.Text)
+					case logger.GoAPI:
+						how = fmt.Sprintf("'Conditions: []string{%q}'", key.Text)
+					}
+					r.debugMeta.notes = append(r.debugMeta.notes, tracker.MsgData(key.Range,
+						fmt.Sprintf("Consider enabling the %q condition if this package expects it to be enabled. "+
+							"You can use %s to do that.", key.Text, how)))
+					didSuggestEnablingCondition = true
+				}
 			}
 		}
 	}