Merge pull request #426 from supabase/feat/relationship-cardinality

feat: determine relationship cardinality from types
supabase · May 26, 2023 · 56376c0 · 56376c0
2 parents 878034b + fc59958
commit 56376c0
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Showing 6 changed files with 201 additions and 80 deletions.
diff --git a/src/PostgrestFilterBuilder.ts b/src/PostgrestFilterBuilder.ts
@@ -28,8 +28,9 @@ type FilterOperator =
 export default class PostgrestFilterBuilder<
   Schema extends GenericSchema,
   Row extends Record<string, unknown>,
-  Result
-> extends PostgrestTransformBuilder<Schema, Row, Result> {
+  Result,
+  Relationships = unknown
+> extends PostgrestTransformBuilder<Schema, Row, Result, Relationships> {
   eq<ColumnName extends string & keyof Row>(column: ColumnName, value: Row[ColumnName]): this
   eq(column: string, value: unknown): this
   /**

diff --git a/src/PostgrestQueryBuilder.ts b/src/PostgrestQueryBuilder.ts
@@ -5,7 +5,8 @@ import { Fetch, GenericSchema, GenericTable, GenericView } from './types'
 
 export default class PostgrestQueryBuilder<
   Schema extends GenericSchema,
-  Relation extends GenericTable | GenericView
+  Relation extends GenericTable | GenericView,
+  Relationships = Relation extends { Relationships: infer R } ? R : unknown
 > {
   url: URL
   headers: Record<string, string>
@@ -52,7 +53,10 @@ export default class PostgrestQueryBuilder<
    * `"estimated"`: Uses exact count for low numbers and planned count for high
    * numbers.
    */
-  select<Query extends string = '*', ResultOne = GetResult<Schema, Relation['Row'], Query>>(
+  select<
+    Query extends string = '*',
+    ResultOne = GetResult<Schema, Relation['Row'], Relationships, Query>
+  >(
     columns?: Query,
     {
       head = false,
@@ -61,7 +65,7 @@ export default class PostgrestQueryBuilder<
       head?: boolean
       count?: 'exact' | 'planned' | 'estimated'
     } = {}
-  ): PostgrestFilterBuilder<Schema, Relation['Row'], ResultOne[]> {
+  ): PostgrestFilterBuilder<Schema, Relation['Row'], ResultOne[], Relationships> {
     const method = head ? 'HEAD' : 'GET'
     // Remove whitespaces except when quoted
     let quoted = false
@@ -126,7 +130,7 @@ export default class PostgrestQueryBuilder<
       count?: 'exact' | 'planned' | 'estimated'
       defaultToNull?: boolean
     } = {}
-  ): PostgrestFilterBuilder<Schema, Relation['Row'], null> {
+  ): PostgrestFilterBuilder<Schema, Relation['Row'], null, Relationships> {
     const method = 'POST'
 
     const prefersHeaders = []
@@ -211,7 +215,7 @@ export default class PostgrestQueryBuilder<
       count?: 'exact' | 'planned' | 'estimated'
       defaultToNull?: boolean
     } = {}
-  ): PostgrestFilterBuilder<Schema, Relation['Row'], null> {
+  ): PostgrestFilterBuilder<Schema, Relation['Row'], null, Relationships> {
     const method = 'POST'
 
     const prefersHeaders = [`resolution=${ignoreDuplicates ? 'ignore' : 'merge'}-duplicates`]
@@ -275,7 +279,7 @@ export default class PostgrestQueryBuilder<
     }: {
       count?: 'exact' | 'planned' | 'estimated'
     } = {}
-  ): PostgrestFilterBuilder<Schema, Relation['Row'], null> {
+  ): PostgrestFilterBuilder<Schema, Relation['Row'], null, Relationships> {
     const method = 'PATCH'
     const prefersHeaders = []
     if (this.headers['Prefer']) {
@@ -320,7 +324,7 @@ export default class PostgrestQueryBuilder<
     count,
   }: {
     count?: 'exact' | 'planned' | 'estimated'
-  } = {}): PostgrestFilterBuilder<Schema, Relation['Row'], null> {
+  } = {}): PostgrestFilterBuilder<Schema, Relation['Row'], null, Relationships> {
     const method = 'DELETE'
     const prefersHeaders = []
     if (count) {

diff --git a/src/PostgrestTransformBuilder.ts b/src/PostgrestTransformBuilder.ts
@@ -5,7 +5,8 @@ import { GenericSchema } from './types'
 export default class PostgrestTransformBuilder<
   Schema extends GenericSchema,
   Row extends Record<string, unknown>,
-  Result
+  Result,
+  Relationships = unknown
 > extends PostgrestBuilder<Result> {
   /**
    * Perform a SELECT on the query result.
@@ -16,9 +17,9 @@ export default class PostgrestTransformBuilder<
    *
    * @param columns - The columns to retrieve, separated by commas
    */
-  select<Query extends string = '*', NewResultOne = GetResult<Schema, Row, Query>>(
+  select<Query extends string = '*', NewResultOne = GetResult<Schema, Row, Relationships, Query>>(
     columns?: Query
-  ): PostgrestTransformBuilder<Schema, Row, NewResultOne[]> {
+  ): PostgrestTransformBuilder<Schema, Row, NewResultOne[], Relationships> {
     // Remove whitespaces except when quoted
     let quoted = false
     const cleanedColumns = (columns ?? '*')
@@ -38,7 +39,7 @@ export default class PostgrestTransformBuilder<
       this.headers['Prefer'] += ','
     }
     this.headers['Prefer'] += 'return=representation'
-    return this as unknown as PostgrestTransformBuilder<Schema, Row, NewResultOne[]>
+    return this as unknown as PostgrestTransformBuilder<Schema, Row, NewResultOne[], Relationships>
   }
 
   order<ColumnName extends string & keyof Row>(
@@ -249,7 +250,7 @@ export default class PostgrestTransformBuilder<
    *
    * @typeParam NewResult - The new result type to override with
    */
-  returns<NewResult>(): PostgrestTransformBuilder<Schema, Row, NewResult> {
-    return this as unknown as PostgrestTransformBuilder<Schema, Row, NewResult>
+  returns<NewResult>(): PostgrestTransformBuilder<Schema, Row, NewResult, Relationships> {
+    return this as unknown as PostgrestTransformBuilder<Schema, Row, NewResult, Relationships>
   }
 }
diff --git a/src/select-query-parser.ts b/src/select-query-parser.ts
@@ -65,6 +65,26 @@ type EatWhitespace<Input extends string> = string extends Input
   ? EatWhitespace<Remainder>
   : Input
 
+type HasFKey<FKeyName, Relationships> = Relationships extends [infer R]
+  ? R extends { foreignKeyName: FKeyName }
+    ? true
+    : false
+  : Relationships extends [infer R, ...infer Rest]
+  ? HasFKey<FKeyName, [R]> extends true
+    ? true
+    : HasFKey<FKeyName, Rest>
+  : false
+
+type HasFKeyToFRel<FRelName, Relationships> = Relationships extends [infer R]
+  ? R extends { referencedRelation: FRelName }
+    ? true
+    : false
+  : Relationships extends [infer R, ...infer Rest]
+  ? HasFKeyToFRel<FRelName, [R]> extends true
+    ? true
+    : HasFKeyToFRel<FRelName, Rest>
+  : false
+
 /**
  * Constructs a type definition for a single field of an object.
  *
@@ -75,20 +95,44 @@ type EatWhitespace<Input extends string> = string extends Input
 type ConstructFieldDefinition<
   Schema extends GenericSchema,
   Row extends Record<string, unknown>,
+  Relationships,
   Field
-> = Field extends {
-  star: true
-}
+> = Field extends { star: true }
   ? Row
+  : Field extends { name: string; original: string; hint: string; children: unknown[] }
+  ? {
+      [_ in Field['name']]: GetResultHelper<
+        Schema,
+        (Schema['Tables'] & Schema['Views'])[Field['original']]['Row'],
+        (Schema['Tables'] & Schema['Views'])[Field['original']] extends { Relationships: infer R }
+          ? R
+          : unknown,
+        Field['children'],
+        unknown
+      > extends infer Child
+        ? Relationships extends unknown[]
+          ? HasFKey<Field['hint'], Relationships> extends true
+            ? Child | null
+            : Child[]
+          : Child[]
+        : never
+    }
   : Field extends { name: string; original: string; children: unknown[] }
   ? {
       [_ in Field['name']]: GetResultHelper<
         Schema,
         (Schema['Tables'] & Schema['Views'])[Field['original']]['Row'],
+        (Schema['Tables'] & Schema['Views'])[Field['original']] extends { Relationships: infer R }
+          ? R
+          : unknown,
         Field['children'],
         unknown
       > extends infer Child
-        ? Child | Child[] | null
+        ? Relationships extends unknown[]
+          ? HasFKeyToFRel<Field['original'], Relationships> extends true
+            ? Child | null
+            : Child[]
+          : Child[]
         : never
     }
   : Field extends { name: string; original: string }
@@ -191,14 +235,14 @@ type ParseNode<Input extends string> = Input extends ''
       ? ParseEmbeddedResource<EatWhitespace<Remainder>>
       : ParserError<'Expected embedded resource after `!inner`'>
     : EatWhitespace<Remainder> extends `!${infer Remainder}`
-    ? ParseIdentifier<EatWhitespace<Remainder>> extends [infer _Hint, `${infer Remainder}`]
+    ? ParseIdentifier<EatWhitespace<Remainder>> extends [infer Hint, `${infer Remainder}`]
       ? EatWhitespace<Remainder> extends `!inner${infer Remainder}`
         ? ParseEmbeddedResource<EatWhitespace<Remainder>> extends [
             infer Fields,
             `${infer Remainder}`
           ]
           ? // `field!hint!inner(nodes)`
-            [{ name: Name; original: Name; children: Fields }, EatWhitespace<Remainder>]
+            [{ name: Name; original: Name; hint: Hint; children: Fields }, EatWhitespace<Remainder>]
           : ParseEmbeddedResource<EatWhitespace<Remainder>> extends ParserError<string>
           ? ParseEmbeddedResource<EatWhitespace<Remainder>>
           : ParserError<'Expected embedded resource after `!inner`'>
@@ -207,7 +251,7 @@ type ParseNode<Input extends string> = Input extends ''
             `${infer Remainder}`
           ]
         ? // `field!hint(nodes)`
-          [{ name: Name; original: Name; children: Fields }, EatWhitespace<Remainder>]
+          [{ name: Name; original: Name; hint: Hint; children: Fields }, EatWhitespace<Remainder>]
         : ParseEmbeddedResource<EatWhitespace<Remainder>> extends ParserError<string>
         ? ParseEmbeddedResource<EatWhitespace<Remainder>>
         : ParserError<'Expected embedded resource after `!hint`'>
@@ -225,14 +269,17 @@ type ParseNode<Input extends string> = Input extends ''
           ? ParseEmbeddedResource<EatWhitespace<Remainder>>
           : ParserError<'Expected embedded resource after `!inner`'>
         : EatWhitespace<Remainder> extends `!${infer Remainder}`
-        ? ParseIdentifier<EatWhitespace<Remainder>> extends [infer _Hint, `${infer Remainder}`]
+        ? ParseIdentifier<EatWhitespace<Remainder>> extends [infer Hint, `${infer Remainder}`]
           ? EatWhitespace<Remainder> extends `!inner${infer Remainder}`
             ? ParseEmbeddedResource<EatWhitespace<Remainder>> extends [
                 infer Fields,
                 `${infer Remainder}`
               ]
               ? // `renamed_field:field!hint!inner(nodes)`
-                [{ name: Name; original: OriginalName; children: Fields }, EatWhitespace<Remainder>]
+                [
+                  { name: Name; original: OriginalName; hint: Hint; children: Fields },
+                  EatWhitespace<Remainder>
+                ]
               : ParseEmbeddedResource<EatWhitespace<Remainder>> extends ParserError<string>
               ? ParseEmbeddedResource<EatWhitespace<Remainder>>
               : ParserError<'Expected embedded resource after `!inner`'>
@@ -245,6 +292,7 @@ type ParseNode<Input extends string> = Input extends ''
                 {
                   name: Name
                   original: OriginalName
+                  hint: Hint
                   children: Fields
                 },
                 EatWhitespace<Remainder>
@@ -363,12 +411,25 @@ type ParseQuery<Query extends string> = string extends Query
 type GetResultHelper<
   Schema extends GenericSchema,
   Row extends Record<string, unknown>,
+  Relationships,
   Fields extends unknown[],
   Acc
 > = Fields extends [infer R]
-  ? GetResultHelper<Schema, Row, [], ConstructFieldDefinition<Schema, Row, R> & Acc>
+  ? GetResultHelper<
+      Schema,
+      Row,
+      Relationships,
+      [],
+      ConstructFieldDefinition<Schema, Row, Relationships, R> & Acc
+    >
   : Fields extends [infer R, ...infer Rest]
-  ? GetResultHelper<Schema, Row, Rest, ConstructFieldDefinition<Schema, Row, R> & Acc>
+  ? GetResultHelper<
+      Schema,
+      Row,
+      Relationships,
+      Rest,
+      ConstructFieldDefinition<Schema, Row, Relationships, R> & Acc
+    >
   : Prettify<Acc>
 
 /**
@@ -380,7 +441,8 @@ type GetResultHelper<
 export type GetResult<
   Schema extends GenericSchema,
   Row extends Record<string, unknown>,
+  Relationships,
   Query extends string
 > = ParseQuery<Query> extends unknown[]
-  ? GetResultHelper<Schema, Row, ParseQuery<Query>, unknown>
+  ? GetResultHelper<Schema, Row, Relationships, ParseQuery<Query>, unknown>
   : ParseQuery<Query>
diff --git a/test/index.test-d.ts b/test/index.test-d.ts
@@ -63,3 +63,21 @@ const postgrest = new PostgrestClient<Database>(REST_URL)
   }
   expectType<'ONLINE' | 'OFFLINE'>(data)
 }
+
+// many-to-one relationship
+{
+  const { data: message, error } = await postgrest.from('messages').select('user:users(*)').single()
+  if (error) {
+    throw new Error(error.message)
+  }
+  expectType<Database['public']['Tables']['users']['Row'] | null>(message.user)
+}
+
+// one-to-many relationship
+{
+  const { data: user, error } = await postgrest.from('users').select('messages(*)').single()
+  if (error) {
+    throw new Error(error.message)
+  }
+  expectType<Database['public']['Tables']['messages']['Row'][]>(user.messages)
+}