From 3942ef551a0ac9e291150af9a79a102c432a2d49 Mon Sep 17 00:00:00 2001
From: James Yopp <git@jyopp.com>
Date: Thu, 22 Apr 2021 14:25:07 -0700
Subject: [PATCH] Add Context.ResultBlob, function tests

---
 func.go      |   3 ++
 func_test.go | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 117 insertions(+)

diff --git a/func.go b/func.go
index e080599..75421d9 100644
--- a/func.go
+++ b/func.go
@@ -72,6 +72,9 @@ func (ctx Context) ResultFloat(v float64)  { C.sqlite3_result_double(ctx.ptr, C.
 func (ctx Context) ResultNull()            { C.sqlite3_result_null(ctx.ptr) }
 func (ctx Context) ResultValue(v Value)    { C.sqlite3_result_value(ctx.ptr, v.ptr) }
 func (ctx Context) ResultZeroBlob(n int64) { C.sqlite3_result_zeroblob64(ctx.ptr, C.sqlite3_uint64(n)) }
+func (ctx Context) ResultBlob(v []byte) {
+	C.sqlite3_result_blob(ctx.ptr, C.CBytes(v), C.int(len(v)), (*[0]byte)(C.cfree))
+}
 func (ctx Context) ResultText(v string) {
 	var cv *C.char
 	if len(v) != 0 {
diff --git a/func_test.go b/func_test.go
index 3a7fb20..ddbf711 100644
--- a/func_test.go
+++ b/func_test.go
@@ -15,6 +15,9 @@
 package sqlite_test
 
 import (
+	"bytes"
+	"errors"
+	"strings"
 	"testing"
 
 	"crawshaw.io/sqlite"
@@ -123,3 +126,114 @@ func TestAggFunc(t *testing.T) {
 	}
 	stmt.Finalize()
 }
+
+func TestBlobFunc(t *testing.T) {
+	c, err := sqlite.OpenConn(":memory:", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := c.Close(); err != nil {
+			t.Error(err)
+		}
+	}()
+
+	xFunc := func(ctx sqlite.Context, values ...sqlite.Value) {
+		var buf bytes.Buffer
+		for _, v := range values {
+			buf.Write(v.Blob())
+		}
+		ctx.ResultBlob(buf.Bytes())
+	}
+	if err := c.CreateFunction("blobcat", true, -1, xFunc, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+
+	stmt, _, err := c.PrepareTransient("SELECT blobcat(x'ff00',x'00ba');")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := stmt.Step(); err != nil {
+		t.Fatal(err)
+	}
+	got := make([]byte, 4)
+	want := []byte{0xFF, 0x00, 0x00, 0xBA}
+	if stmt.ColumnBytes(0, got) != len(want) || !bytes.Equal(got, want) {
+		t.Errorf("blobcat(x'ff00',x'00ba')='%x', want '%x'", got, want)
+	}
+	stmt.Finalize()
+}
+
+func TestStringFunc(t *testing.T) {
+	c, err := sqlite.OpenConn(":memory:", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := c.Close(); err != nil {
+			t.Error(err)
+		}
+	}()
+
+	xFunc := func(ctx sqlite.Context, values ...sqlite.Value) {
+		var buf strings.Builder
+		for _, v := range values {
+			buf.WriteString(v.Text())
+		}
+		ctx.ResultText(buf.String())
+	}
+	if err := c.CreateFunction("strcat", true, -1, xFunc, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+
+	stmt, _, err := c.PrepareTransient("SELECT strcat('str','','cat');")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := stmt.Step(); err != nil {
+		t.Fatal(err)
+	}
+	if got, want := stmt.ColumnText(0), "strcat"; got != want {
+		t.Errorf("strcat('str','','cat')='%s', want '%s'", got, want)
+	}
+	stmt.Finalize()
+}
+
+func TestErrorFunc(t *testing.T) {
+	c, err := sqlite.OpenConn(":memory:", 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := c.Close(); err != nil {
+			t.Error(err)
+		}
+	}()
+
+	nilValueError := errors.New("nil value encountered")
+	xFunc := func(ctx sqlite.Context, values ...sqlite.Value) {
+		if values[0].Type() == sqlite.SQLITE_NULL {
+			ctx.ResultError(nilValueError)
+		} else {
+			ctx.ResultValue(values[0])
+		}
+	}
+
+	if err := c.CreateFunction("rejectnull", true, 1, xFunc, nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	stmt, _, err := c.PrepareTransient("SELECT rejectnull(NULL);")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = stmt.Step()
+	if err == nil {
+		t.Fatal("rejectnull(NULL) failed to produce an error")
+	}
+	if sqlErr, ok := err.(sqlite.Error); !ok || sqlErr.Msg != nilValueError.Error() {
+		t.Fatal("Error does not match expected description")
+	}
+
+	stmt.Finalize()
+}