From e770b314027dc1258fa6504dde77aad14c8cd7f9 Mon Sep 17 00:00:00 2001
From: Justin Lin <wancat@wancat.cc>
Date: Tue, 26 Aug 2025 19:49:37 +1000
Subject: [PATCH] feat: add mapping functions

---
 cmd/api/main.go               |  6 +++---
 internal/author/controller.go |  6 +++---
 internal/author/mapper.go     | 21 +++++++++++++++++++++
 internal/author/model.go      |  7 +++++++
 internal/author/router.go     |  2 +-
 5 files changed, 35 insertions(+), 7 deletions(-)
 create mode 100644 internal/author/mapper.go
 create mode 100644 internal/author/model.go

diff --git a/cmd/api/main.go b/cmd/api/main.go
index a6f1da0..f56f25e 100644
--- a/cmd/api/main.go
+++ b/cmd/api/main.go
@@ -7,7 +7,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/jackc/pgx/v5"
 
-	user "tutorial.sqlc.dev/app/internal/author"
+	"tutorial.sqlc.dev/app/internal/author"
 )
 
 func run() error {
@@ -20,8 +20,8 @@ func run() error {
 	defer conn.Close(ctx)
 
 	r := gin.Default()
-	userCtl := user.NewController(conn)
-	user.Register(r, &userCtl)
+	authorCtl := author.NewController(conn)
+	author.Register(r, &authorCtl)
 
 	r.Run(":8000")
 	return nil
diff --git a/internal/author/controller.go b/internal/author/controller.go
index 9fa29b3..0333f9a 100644
--- a/internal/author/controller.go
+++ b/internal/author/controller.go
@@ -1,4 +1,4 @@
-package user
+package author
 
 import (
 	"strconv"
@@ -23,7 +23,7 @@ func (u *Controller) ListAuthors(c *gin.Context) {
 		c.AbortWithError(500, err)
 		return
 	}
-	c.JSON(200, authors)
+	c.JSON(200, toAuthorSlice(authors))
 }
 
 func (u *Controller) GetAuthorByID(c *gin.Context) {
@@ -39,5 +39,5 @@ func (u *Controller) GetAuthorByID(c *gin.Context) {
 		return
 	}
 
-	c.JSON(200, author)
+	c.JSON(200, toAuthor(author))
 }
diff --git a/internal/author/mapper.go b/internal/author/mapper.go
new file mode 100644
index 0000000..83c7fc4
--- /dev/null
+++ b/internal/author/mapper.go
@@ -0,0 +1,21 @@
+package author
+
+import "tutorial.sqlc.dev/app/internal/author/gen"
+
+func toAuthor(a gen.Author) Author {
+	return Author{
+		a.ID, a.Name, a.Bio.String,
+	}
+}
+
+func mapSlice[K any, V any](conv func(K) V) func([]K) []V {
+	return func(inputs []K) []V {
+		output := make([]V, len(inputs))
+		for i, input := range inputs {
+			output[i] = conv(input)
+		}
+		return output
+	}
+}
+
+var toAuthorSlice = mapSlice(toAuthor)
diff --git a/internal/author/model.go b/internal/author/model.go
new file mode 100644
index 0000000..d579ede
--- /dev/null
+++ b/internal/author/model.go
@@ -0,0 +1,7 @@
+package author
+
+type Author struct {
+	ID   int64  `json:"id"`
+	Name string `json:"name"`
+	Bio  string `json:"bio"`
+}
diff --git a/internal/author/router.go b/internal/author/router.go
index a5b20b1..a3a66e0 100644
--- a/internal/author/router.go
+++ b/internal/author/router.go
@@ -1,4 +1,4 @@
-package user
+package author
 
 import "github.com/gin-gonic/gin"