Add Effect.Do notation diagnostic (#722)

mattiamanzati · web-flow · commit 6f1985880817 · 2026-04-08T23:19:52.000+02:00
diff --git a/.changeset/sour-lobsters-shop.md b/.changeset/sour-lobsters-shop.md
@@ -0,0 +1,18 @@
+---
+"@effect/language-service": minor
+---
+
+Add the `effectDoNotation` style diagnostic for `Effect.Do` usage and suggest migrating to `Effect.gen` or `Effect.fn`.
+
+Example:
+
+```ts
+import { pipe } from "effect/Function"
+import { Effect } from "effect"
+
+const program = pipe(
+  Effect.Do,
+  Effect.bind("a", () => Effect.succeed(1)),
+  Effect.let("b", ({ a }) => a + 1)
+)
+```
diff --git a/README.md b/README.md
@@ -112,6 +112,7 @@ Some diagnostics are off by default or have a default severity of suggestion, bu
     <tr><td colspan="6"><strong>Style</strong> <em>Cleanup, consistency, and idiomatic Effect code.</em></td></tr>
     <tr><td><code>catchAllToMapError</code></td><td>💡</td><td>🔧</td><td>Suggests using Effect.mapError instead of Effect.catchAll when the callback only wraps the error with Effect.fail</td><td>✓</td><td>✓</td></tr>
     <tr><td><code>deterministicKeys</code></td><td>➖</td><td>🔧</td><td>Enforces deterministic naming for service/tag/error identifiers based on class names</td><td>✓</td><td>✓</td></tr>
+    <tr><td><code>effectDoNotation</code></td><td>➖</td><td></td><td>Suggests using Effect.gen or Effect.fn instead of the Effect.Do notation helpers</td><td>✓</td><td>✓</td></tr>
     <tr><td><code>effectFnOpportunity</code></td><td>💡</td><td>🔧</td><td>Suggests using Effect.fn for functions that returns an Effect</td><td>✓</td><td>✓</td></tr>
     <tr><td><code>effectMapVoid</code></td><td>💡</td><td>🔧</td><td>Suggests using Effect.asVoid instead of Effect.map(() =&gt; void 0), Effect.map(() =&gt; undefined), or Effect.map(() =&gt; {})</td><td>✓</td><td>✓</td></tr>
     <tr><td><code>effectSucceedWithVoid</code></td><td>💡</td><td>🔧</td><td>Suggests using Effect.void instead of Effect.succeed(undefined) or Effect.succeed(void 0)</td><td>✓</td><td>✓</td></tr>
diff --git a/packages/harness-effect-v3/__snapshots__/completions.test.ts.snap b/packages/harness-effect-v3/__snapshots__/completions.test.ts.snap
@@ -248,7 +248,7 @@ exports[`Completion effectDataClasses > effectDataClasses_directImportTaggedErro
 exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:5 1`] = `
 [
   {
-    "insertText": "@effect-diagnostics \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
+    "insertText": "@effect-diagnostics \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
     "isSnippet": true,
     "kind": "string",
     "name": "@effect-diagnostics",
@@ -259,7 +259,7 @@ exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:
     "sortText": "11",
   },
   {
-    "insertText": "@effect-diagnostics-next-line \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
+    "insertText": "@effect-diagnostics-next-line \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
     "isSnippet": true,
     "kind": "string",
     "name": "@effect-diagnostics-next-line",
diff --git a/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation.ts.codefixes b/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation.ts.codefixes
@@ -0,0 +1,6 @@
+effectDoNotation_skipNextLine from 111 to 120
+effectDoNotation_skipFile from 111 to 120
+effectDoNotation_skipNextLine from 241 to 249
+effectDoNotation_skipFile from 241 to 249
+effectDoNotation_skipNextLine from 155 to 164
+effectDoNotation_skipFile from 155 to 164
diff --git a/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation.ts.output b/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation.ts.output
@@ -0,0 +1,8 @@
+Effect.Do
+4:22 - 4:31 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
+
+Effect.Do
+6:33 - 6:42 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
+
+alias.Do
+9:23 - 9:31 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
diff --git a/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation_preview.ts.codefixes b/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation_preview.ts.codefixes
@@ -0,0 +1,2 @@
+effectDoNotation_skipNextLine from 188 to 197
+effectDoNotation_skipFile from 188 to 197
diff --git a/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation_preview.ts.output b/packages/harness-effect-v3/__snapshots__/diagnostics/effectDoNotation_preview.ts.output
@@ -0,0 +1,2 @@
+Effect.Do
+7:2 - 7:11 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
diff --git a/packages/harness-effect-v3/examples/diagnostics/effectDoNotation.ts b/packages/harness-effect-v3/examples/diagnostics/effectDoNotation.ts
@@ -0,0 +1,12 @@
+// @effect-diagnostics effectDoNotation:warning
+import * as Effect from "effect/Effect"
+
+export const direct = Effect.Do
+
+export const piped = Effect.bind(Effect.Do, "a", () => Effect.succeed(1))
+
+const alias = Effect
+export const aliased = alias.Do
+
+const local = { Do: 1 }
+export const shouldNotReport = local.Do
diff --git a/packages/harness-effect-v3/examples/diagnostics/effectDoNotation_preview.ts b/packages/harness-effect-v3/examples/diagnostics/effectDoNotation_preview.ts
@@ -0,0 +1,11 @@
+// @effect-diagnostics *:off
+// @effect-diagnostics effectDoNotation:warning
+import * as Effect from "effect/Effect"
+import { pipe } from "effect/Function"
+
+export const preview = pipe(
+  Effect.Do,
+  Effect.bind("a", () => Effect.succeed(1)),
+  Effect.let("b", ({ a }) => a + 1),
+  Effect.bind("c", ({ b }) => Effect.succeed(b.toString()))
+)
diff --git a/packages/harness-effect-v4/__snapshots__/completions.test.ts.snap b/packages/harness-effect-v4/__snapshots__/completions.test.ts.snap
@@ -109,7 +109,7 @@ exports[`Completion effectDataClasses > effectDataClasses.ts at 4:35 1`] = `
 exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:5 1`] = `
 [
   {
-    "insertText": "@effect-diagnostics \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
+    "insertText": "@effect-diagnostics \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
     "isSnippet": true,
     "kind": "string",
     "name": "@effect-diagnostics",
@@ -120,7 +120,7 @@ exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:
     "sortText": "11",
   },
   {
-    "insertText": "@effect-diagnostics-next-line \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
+    "insertText": "@effect-diagnostics-next-line \${1|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors|}:\${2|off,warning,error,message,suggestion|}$0",
     "isSnippet": true,
     "kind": "string",
     "name": "@effect-diagnostics-next-line",
diff --git a/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation.ts.codefixes b/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation.ts.codefixes
@@ -0,0 +1,6 @@
+effectDoNotation_skipNextLine from 103 to 112
+effectDoNotation_skipFile from 103 to 112
+effectDoNotation_skipNextLine from 233 to 241
+effectDoNotation_skipFile from 233 to 241
+effectDoNotation_skipNextLine from 147 to 156
+effectDoNotation_skipFile from 147 to 156
diff --git a/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation.ts.output b/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation.ts.output
@@ -0,0 +1,8 @@
+Effect.Do
+4:22 - 4:31 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
+
+Effect.Do
+6:33 - 6:42 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
+
+alias.Do
+9:23 - 9:31 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
diff --git a/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation_preview.ts.codefixes b/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation_preview.ts.codefixes
@@ -0,0 +1,2 @@
+effectDoNotation_skipNextLine from 180 to 189
+effectDoNotation_skipFile from 180 to 189
diff --git a/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation_preview.ts.output b/packages/harness-effect-v4/__snapshots__/diagnostics/effectDoNotation_preview.ts.output
@@ -0,0 +1,2 @@
+Effect.Do
+7:2 - 7:11 | 0 | This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes.    effect(effectDoNotation)
diff --git a/packages/harness-effect-v4/examples/diagnostics/effectDoNotation.ts b/packages/harness-effect-v4/examples/diagnostics/effectDoNotation.ts
@@ -0,0 +1,12 @@
+// @effect-diagnostics effectDoNotation:warning
+import { Effect } from "effect"
+
+export const direct = Effect.Do
+
+export const piped = Effect.bind(Effect.Do, "a", () => Effect.succeed(1))
+
+const alias = Effect
+export const aliased = alias.Do
+
+const local = { Do: 1 }
+export const shouldNotReport = local.Do
diff --git a/packages/harness-effect-v4/examples/diagnostics/effectDoNotation_preview.ts b/packages/harness-effect-v4/examples/diagnostics/effectDoNotation_preview.ts
@@ -0,0 +1,11 @@
+// @effect-diagnostics *:off
+// @effect-diagnostics effectDoNotation:warning
+import { Effect } from "effect"
+import { pipe } from "effect/Function"
+
+export const preview = pipe(
+  Effect.Do,
+  Effect.bind("a", () => Effect.succeed(1)),
+  Effect.let("b", ({ a }) => a + 1),
+  Effect.bind("c", ({ b }) => Effect.succeed(b.toString()))
+)
diff --git a/packages/language-service/src/diagnostics.ts b/packages/language-service/src/diagnostics.ts
@@ -7,6 +7,7 @@ import { cryptoRandomUUID } from "./diagnostics/cryptoRandomUUID.js"
 import { cryptoRandomUUIDInEffect } from "./diagnostics/cryptoRandomUUIDInEffect.js"
 import { deterministicKeys } from "./diagnostics/deterministicKeys.js"
 import { duplicatePackage } from "./diagnostics/duplicatePackage.js"
+import { effectDoNotation } from "./diagnostics/effectDoNotation.js"
 import { effectFnIife } from "./diagnostics/effectFnIife.js"
 import { effectFnImplicitAny } from "./diagnostics/effectFnImplicitAny.js"
 import { effectFnOpportunity } from "./diagnostics/effectFnOpportunity.js"
@@ -83,6 +84,7 @@ export const diagnostics = [
   cryptoRandomUUID,
   cryptoRandomUUIDInEffect,
   duplicatePackage,
+  effectDoNotation,
   effectFnImplicitAny,
   effectGenUsesAdapter,
   missingEffectContext,
diff --git a/packages/language-service/src/diagnostics/effectDoNotation.ts b/packages/language-service/src/diagnostics/effectDoNotation.ts
diff --git a/packages/language-service/src/diagnostics/outdatedApi.db.ts b/packages/language-service/src/diagnostics/outdatedApi.db.ts
diff --git a/packages/language-service/src/metadata.json b/packages/language-service/src/metadata.json
diff --git a/schema.json b/schema.json

Original file line number	Diff line number	Diff line change
@@ -248,7 +248,7 @@ exports[`Completion effectDataClasses > effectDataClasses_directImportTaggedErro
`248`	`248`	exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:5 1`] = `
`249`	`249`	`[`
`250`	`250`	`{`
`251`		- "insertText": "@effect-diagnostics \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
	`251`	+ "insertText": "@effect-diagnostics \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
`252`	`252`	`"isSnippet": true,`
`253`	`253`	`"kind": "string",`
`254`	`254`	`"name": "@effect-diagnostics",`
@@ -259,7 +259,7 @@ exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:
`259`	`259`	`"sortText": "11",`
`260`	`260`	`},`
`261`	`261`	`{`
`262`		- "insertText": "@effect-diagnostics-next-line \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
	`262`	+ "insertText": "@effect-diagnostics-next-line \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
`263`	`263`	`"isSnippet": true,`
`264`	`264`	`"kind": "string",`
`265`	`265`	`"name": "@effect-diagnostics-next-line",`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+effectDoNotation_skipNextLine from 188 to 197`
	`2`	`+effectDoNotation_skipFile from 188 to 197`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Effect.Do`
	`2`	+7:2 - 7:11 \| 0 \| This uses the Effect do emulation. `Effect.gen` or `Effect.fn` achieve the same result with native JS scopes. effect(effectDoNotation)
Original file line number	Diff line number	Diff line change
@@ -109,7 +109,7 @@ exports[`Completion effectDataClasses > effectDataClasses.ts at 4:35 1`] = `
`109`	`109`	exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:5 1`] = `
`110`	`110`	`[`
`111`	`111`	`{`
`112`		- "insertText": "@effect-diagnostics \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
	`112`	+ "insertText": "@effect-diagnostics \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
`113`	`113`	`"isSnippet": true,`
`114`	`114`	`"kind": "string",`
`115`	`115`	`"name": "@effect-diagnostics",`
@@ -120,7 +120,7 @@ exports[`Completion effectDiagnosticsComment > effectDiagnosticsComment.ts at 2:
`120`	`120`	`"sortText": "11",`
`121`	`121`	`},`
`122`	`122`	`{`
`123`		- "insertText": "@effect-diagnostics-next-line \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
	`123`	+ "insertText": "@effect-diagnostics-next-line \${1\|anyUnknownInErrorContext,asyncFunction,catchAllToMapError,catchUnfailableEffect,classSelfMismatch,cryptoRandomUUID,cryptoRandomUUIDInEffect,deterministicKeys,duplicatePackage,effectDoNotation,effectFnIife,effectFnImplicitAny,effectFnOpportunity,effectGenUsesAdapter,effectInFailure,effectInVoidSuccess,effectMapVoid,effectSucceedWithVoid,extendsNativeError,floatingEffect,genericEffectServices,globalConsole,globalConsoleInEffect,globalDate,globalDateInEffect,globalErrorInEffectCatch,globalErrorInEffectFailure,globalFetch,globalFetchInEffect,globalRandom,globalRandomInEffect,globalTimers,globalTimersInEffect,importFromBarrel,instanceOfSchema,layerMergeAllWithDependencies,lazyPromiseInEffectSync,leakingRequirements,missedPipeableOpportunity,missingEffectContext,missingEffectError,missingEffectServiceDependency,missingLayerContext,missingReturnYieldStar,missingStarInYieldEffectGen,multipleEffectProvide,nestedEffectGenYield,newPromise,nodeBuiltinImport,nonObjectEffectServiceType,outdatedApi,outdatedEffectCodegen,overriddenSchemaConstructor,preferSchemaOverJson,processEnv,processEnvInEffect,redundantSchemaTagIdentifier,returnEffectInGen,runEffectInsideEffect,schemaStructWithTag,schemaSyncInEffect,schemaUnionOfLiterals,scopeInLayerEffect,serviceNotAsClass,strictBooleanExpressions,strictEffectProvide,tryCatchInEffectGen,unknownInEffectCatch,unnecessaryArrowBlock,unnecessaryEffectGen,unnecessaryFailYieldableError,unnecessaryPipe,unnecessaryPipeChain,unsupportedServiceAccessors\|}:\${2\|off,warning,error,message,suggestion\|}$0",
`124`	`124`	`"isSnippet": true,`
`125`	`125`	`"kind": "string",`
`126`	`126`	`"name": "@effect-diagnostics-next-line",`