Add agent library

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/agent/approval_test.go

@@ -0,0 +1,203 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package agent
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.probo.inc/probo/pkg/llm"
+)
+
+func TestBuildToolNameSet(t *testing.T) {
+	t.Parallel()
+
+	t.Run(
+		"nil input returns nil",
+		func(t *testing.T) {
+			t.Parallel()
+
+			assert.Nil(t, buildToolNameSet(nil))
+		},
+	)
+
+	t.Run(
+		"empty slice returns nil",
+		func(t *testing.T) {
+			t.Parallel()
+
+			assert.Nil(t, buildToolNameSet([]string{}))
+		},
+	)
+
+	t.Run(
+		"single name",
+		func(t *testing.T) {
+			t.Parallel()
+
+			set := buildToolNameSet([]string{"delete"})
+
+			assert.Len(t, set, 1)
+			_, ok := set["delete"]
+			assert.True(t, ok)
+		},
+	)
+
+	t.Run(
+		"multiple names",
+		func(t *testing.T) {
+			t.Parallel()
+
+			set := buildToolNameSet([]string{"delete", "update", "create"})
+
+			assert.Len(t, set, 3)
+			for _, name := range []string{"delete", "update", "create"} {
+				_, ok := set[name]
+				assert.True(t, ok, "expected set to contain %q", name)
+			}
+		},
+	)
+
+	t.Run(
+		"duplicate names are deduplicated",
+		func(t *testing.T) {
+			t.Parallel()
+
+			set := buildToolNameSet([]string{"delete", "delete", "update"})
+
+			assert.Len(t, set, 2)
+		},
+	)
+}
+
+func TestApprovalConfig_RequiresApproval(t *testing.T) {
+	t.Parallel()
+
+	tc := llm.ToolCall{
+		ID:       "tc_1",
+		Function: llm.FunctionCall{Name: "delete_user", Arguments: `{}`},
+	}
+
+	t.Run(
+		"nil config returns false",
+		func(t *testing.T) {
+			t.Parallel()
+
+			var c *ApprovalConfig
+			assert.False(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+
+	t.Run(
+		"empty config returns false",
+		func(t *testing.T) {
+			t.Parallel()
+
+			c := &ApprovalConfig{}
+			assert.False(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+
+	t.Run(
+		"tool name in set returns true",
+		func(t *testing.T) {
+			t.Parallel()
+
+			c := &ApprovalConfig{
+				toolNameSet: map[string]struct{}{
+					"delete_user": {},
+				},
+			}
+
+			assert.True(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+
+	t.Run(
+		"tool name not in set returns false",
+		func(t *testing.T) {
+			t.Parallel()
+
+			c := &ApprovalConfig{
+				toolNameSet: map[string]struct{}{
+					"list_users": {},
+				},
+			}
+
+			assert.False(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+
+	t.Run(
+		"ShouldApprove takes precedence over tool name set",
+		func(t *testing.T) {
+			t.Parallel()
+
+			c := &ApprovalConfig{
+				toolNameSet: map[string]struct{}{
+					"delete_user": {},
+				},
+				ShouldApprove: func(_ context.Context, _ llm.ToolCall) bool {
+					return false
+				},
+			}
+
+			assert.False(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+
+	t.Run(
+		"ShouldApprove receives context and tool call",
+		func(t *testing.T) {
+			t.Parallel()
+
+			type ctxKey struct{}
+			ctx := context.WithValue(context.Background(), ctxKey{}, "marker")
+
+			var capturedCtx context.Context
+			var capturedTC llm.ToolCall
+
+			c := &ApprovalConfig{
+				ShouldApprove: func(ctx context.Context, tc llm.ToolCall) bool {
+					capturedCtx = ctx
+					capturedTC = tc
+					return true
+				},
+			}
+
+			result := c.requiresApproval(ctx, tc)
+
+			assert.True(t, result)
+			assert.Equal(t, "marker", capturedCtx.Value(ctxKey{}))
+			assert.Equal(t, "delete_user", capturedTC.Function.Name)
+		},
+	)
+
+	t.Run(
+		"ShouldApprove returning true requires approval",
+		func(t *testing.T) {
+			t.Parallel()
+
+			c := &ApprovalConfig{
+				ShouldApprove: func(_ context.Context, _ llm.ToolCall) bool {
+					return true
+				},
+			}
+
+			assert.True(t, c.requiresApproval(context.Background(), tc))
+		},
+	)
+}