From 4aaeeb26bb642ad8ba44959e1720433cb6e163bd Mon Sep 17 00:00:00 2001
From: Travis Arnold <ftntravis@gmail.com>
Date: Sun, 14 Jul 2024 12:46:47 -0700
Subject: [PATCH] better component analysis

---
 .../src/types/getTypeDocumentation.test.ts    | 12 ++--
 packages/utils/src/types/processType.test.ts  | 55 +++++++++++++++++--
 packages/utils/src/types/processType.ts       | 12 ++--
 3 files changed, 63 insertions(+), 16 deletions(-)

diff --git a/packages/utils/src/types/getTypeDocumentation.test.ts b/packages/utils/src/types/getTypeDocumentation.test.ts
index a07be7f..ab1f911 100644
--- a/packages/utils/src/types/getTypeDocumentation.test.ts
+++ b/packages/utils/src/types/getTypeDocumentation.test.ts
@@ -661,7 +661,7 @@ describe('getTypeDocumentation', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": undefined,
               "description": undefined,
               "filePath": "test.ts",
@@ -1167,7 +1167,7 @@ describe('getTypeDocumentation', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": {
                 "variant": "body1",
               },
@@ -1257,7 +1257,7 @@ describe('getTypeDocumentation', () => {
               {
                 "kind": "ComponentSignature",
                 "modifier": undefined,
-                "properties": {
+                "parameter": {
                   "defaultValue": undefined,
                   "description": undefined,
                   "filePath": "node_modules/@types/react/index.d.ts",
@@ -1404,7 +1404,7 @@ describe('getTypeDocumentation', () => {
               {
                 "kind": "ComponentSignature",
                 "modifier": undefined,
-                "properties": {
+                "parameter": {
                   "defaultValue": undefined,
                   "description": undefined,
                   "filePath": "node_modules/@types/react/index.d.ts",
@@ -3008,7 +3008,7 @@ describe('getTypeDocumentation', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": undefined,
               "description": undefined,
               "filePath": "test.tsx",
@@ -3186,7 +3186,7 @@ describe('getTypeDocumentation', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": undefined,
               "description": undefined,
               "filePath": "test.ts",
diff --git a/packages/utils/src/types/processType.test.ts b/packages/utils/src/types/processType.test.ts
index 517bd0e..7ddfb8f 100644
--- a/packages/utils/src/types/processType.test.ts
+++ b/packages/utils/src/types/processType.test.ts
@@ -2559,7 +2559,7 @@ describe('processProperties', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": undefined,
               "description": undefined,
               "filePath": "test.ts",
@@ -2654,7 +2654,7 @@ describe('processProperties', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": undefined,
               "description": undefined,
               "filePath": "test.ts",
@@ -2717,7 +2717,7 @@ describe('processProperties', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": {
                 "color": "red",
               },
@@ -2785,7 +2785,7 @@ describe('processProperties', () => {
           {
             "kind": "ComponentSignature",
             "modifier": undefined,
-            "properties": {
+            "parameter": {
               "defaultValue": {
                 "style": {
                   "color": "blue",
@@ -3342,7 +3342,7 @@ describe('processProperties', () => {
               {
                 "kind": "ComponentSignature",
                 "modifier": undefined,
-                "properties": {
+                "parameter": {
                   "defaultValue": undefined,
                   "description": undefined,
                   "filePath": "node_modules/styled-components/dist/types.d.ts",
@@ -3389,7 +3389,7 @@ describe('processProperties', () => {
               {
                 "kind": "ComponentSignature",
                 "modifier": undefined,
-                "properties": {
+                "parameter": {
                   "defaultValue": undefined,
                   "description": undefined,
                   "filePath": "node_modules/@types/react/index.d.ts",
@@ -4290,4 +4290,47 @@ describe('processProperties', () => {
       }
     `)
   })
+
+  test('infers component with no parameter from return type', () => {
+    const sourceFile = project.createSourceFile(
+      'test.ts',
+      dedent`
+      import * as React from 'react'
+      export function Text(): React.ReactNode {
+        return null
+      }
+      `,
+      { overwrite: true }
+    )
+    const typeAlias = sourceFile.getFunctionOrThrow('Text')
+    const processedProperties = processType(typeAlias.getType())
+
+    expect(processedProperties).toMatchInlineSnapshot(`
+      {
+        "filePath": "test.ts",
+        "kind": "Component",
+        "name": "Text",
+        "position": {
+          "end": {
+            "column": 2,
+            "line": 4,
+          },
+          "start": {
+            "column": 1,
+            "line": 2,
+          },
+        },
+        "signatures": [
+          {
+            "kind": "ComponentSignature",
+            "modifier": undefined,
+            "parameter": undefined,
+            "returnType": "ReactNode",
+            "type": "function Text(): ReactNode",
+          },
+        ],
+        "type": "() => ReactNode",
+      }
+    `)
+  })
 })
diff --git a/packages/utils/src/types/processType.ts b/packages/utils/src/types/processType.ts
index 5102e32..e2ba224 100644
--- a/packages/utils/src/types/processType.ts
+++ b/packages/utils/src/types/processType.ts
@@ -172,7 +172,7 @@ export interface FunctionType extends BaseType {
 export interface ComponentSignatureType extends BaseType {
   kind: 'ComponentSignature'
   modifier?: 'async' | 'generator'
-  properties: ObjectType
+  parameter?: ObjectType | ReferenceType
   returnType: string
 }
 
@@ -663,7 +663,10 @@ export function processType(
                 return {
                   ...processedCallSignature,
                   kind: 'ComponentSignature',
-                  properties: parameters.at(0)! as ObjectType,
+                  parameter: parameters.at(0) as
+                    | ObjectType
+                    | ReferenceType
+                    | undefined,
                 } satisfies ComponentSignatureType
               }
             ),
@@ -1426,8 +1429,9 @@ export function isComponent(
   }
 
   return callSignatures.every((signature) => {
-    const onlyOneParameter = signature.parameters.length === 1
-    if (onlyOneParameter) {
+    if (signature.returnType === 'ReactNode') {
+      return true
+    } else if (signature.parameters.length === 1) {
       const firstParameter = signature.parameters.at(0)!
 
       if (firstParameter.kind === 'Reference') {