From 70b46058839259da76c8a2838db2a381272eab5f Mon Sep 17 00:00:00 2001
From: Owen Rumney <owen.rumney@aquasec.com>
Date: Thu, 6 Oct 2022 09:10:07 +0100
Subject: [PATCH] feat: add comparison functions (#990)

Signed-off-by: Owen Rumney <owen.rumney@aquasec.com>
---
 pkg/scanners/azure/functions/coalesce.go      |  10 ++
 pkg/scanners/azure/functions/coalesce_test.go |  56 +++++++++
 pkg/scanners/azure/functions/equals.go        |  25 ++++
 pkg/scanners/azure/functions/equals_test.go   | 111 ++++++++++++++++
 pkg/scanners/azure/functions/functions.go     |   6 +
 pkg/scanners/azure/functions/greater.go       |  47 +++++++
 pkg/scanners/azure/functions/greater_test.go  | 119 ++++++++++++++++++
 pkg/scanners/azure/functions/less.go          |  47 +++++++
 pkg/scanners/azure/functions/less_test.go     | 119 ++++++++++++++++++
 9 files changed, 540 insertions(+)
 create mode 100644 pkg/scanners/azure/functions/coalesce.go
 create mode 100644 pkg/scanners/azure/functions/coalesce_test.go
 create mode 100644 pkg/scanners/azure/functions/equals.go
 create mode 100644 pkg/scanners/azure/functions/equals_test.go
 create mode 100644 pkg/scanners/azure/functions/greater.go
 create mode 100644 pkg/scanners/azure/functions/greater_test.go
 create mode 100644 pkg/scanners/azure/functions/less.go
 create mode 100644 pkg/scanners/azure/functions/less_test.go

diff --git a/pkg/scanners/azure/functions/coalesce.go b/pkg/scanners/azure/functions/coalesce.go
new file mode 100644
index 000000000..b7ec26145
--- /dev/null
+++ b/pkg/scanners/azure/functions/coalesce.go
@@ -0,0 +1,10 @@
+package functions
+
+func Coalesce(args ...interface{}) interface{} {
+	for _, arg := range args {
+		if arg != nil {
+			return arg
+		}
+	}
+	return nil
+}
diff --git a/pkg/scanners/azure/functions/coalesce_test.go b/pkg/scanners/azure/functions/coalesce_test.go
new file mode 100644
index 000000000..361914df6
--- /dev/null
+++ b/pkg/scanners/azure/functions/coalesce_test.go
@@ -0,0 +1,56 @@
+package functions
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Coalesce(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+		{
+			name: "coalesce with nil",
+			args: []interface{}{
+				nil,
+			},
+			expected: nil,
+		},
+		{
+			name: "coalesce with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: "test",
+		},
+		{
+			name: "coalesce with nil and string and int",
+			args: []interface{}{
+				nil,
+				"test",
+				1,
+			},
+			expected: "test",
+		},
+		{
+			name: "coalesce with nil and nil and array",
+			args: []interface{}{
+				nil,
+				nil,
+				[]interface{}{"a", "b", "c"},
+			},
+			expected: []interface{}{"a", "b", "c"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := Coalesce(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}
diff --git a/pkg/scanners/azure/functions/equals.go b/pkg/scanners/azure/functions/equals.go
new file mode 100644
index 000000000..ca5174144
--- /dev/null
+++ b/pkg/scanners/azure/functions/equals.go
@@ -0,0 +1,25 @@
+package functions
+
+func Equals(args ...interface{}) interface{} {
+	if len(args) != 2 {
+		return false
+	}
+
+	slice1, ok := args[0].([]interface{})
+	if ok {
+		slice2, ok := args[1].([]interface{})
+		if ok {
+			if len(slice1) != len(slice2) {
+				return false
+			}
+			for i := 0; i < len(slice1); i++ {
+				if slice1[i] != slice2[i] {
+					return false
+				}
+			}
+			return true
+		}
+	}
+
+	return args[0] == args[1]
+}
diff --git a/pkg/scanners/azure/functions/equals_test.go b/pkg/scanners/azure/functions/equals_test.go
new file mode 100644
index 000000000..e9ad7f03f
--- /dev/null
+++ b/pkg/scanners/azure/functions/equals_test.go
@@ -0,0 +1,111 @@
+package functions
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Equals(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+		{
+			name: "equals with nil",
+			args: []interface{}{
+				nil,
+			},
+			expected: false,
+		},
+		{
+			name: "equals with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "equals with nil and string and int",
+			args: []interface{}{
+				nil,
+				"test",
+				1,
+			},
+			expected: false,
+		},
+		{
+			name: "equals with nil and nil and array",
+			args: []interface{}{
+				nil,
+				nil,
+				[]interface{}{"a", "b", "c"},
+			},
+			expected: false,
+		},
+		{
+			name: "equals with nil and nil",
+			args: []interface{}{
+				nil,
+				nil,
+			},
+			expected: true,
+		},
+		{
+			name: "equals with string and string",
+			args: []interface{}{
+				"test",
+				"test",
+			},
+			expected: true,
+		},
+		{
+			name: "equals with string and string",
+			args: []interface{}{
+				"test",
+				"test1",
+			},
+			expected: false,
+		},
+		{
+			name: "equals with int and int",
+			args: []interface{}{
+				1,
+				1,
+			},
+			expected: true,
+		},
+		{
+			name: "equals with int and int",
+			args: []interface{}{
+				1,
+				2,
+			},
+			expected: false,
+		},
+		{
+			name: "equals with array and array",
+			args: []interface{}{
+				[]interface{}{"a", "b", "c"},
+				[]interface{}{"a", "b", "c"},
+			},
+			expected: true,
+		},
+		{
+			name: "equals with array and array",
+			args: []interface{}{
+				[]interface{}{"a", "b", "c"},
+				[]interface{}{"a", "b", "d"},
+			},
+			expected: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := Equals(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}
diff --git a/pkg/scanners/azure/functions/functions.go b/pkg/scanners/azure/functions/functions.go
index 81df40e5c..032b9db7d 100644
--- a/pkg/scanners/azure/functions/functions.go
+++ b/pkg/scanners/azure/functions/functions.go
@@ -43,6 +43,12 @@ var generalFuncs = map[string]func(...interface{}) interface{}{
 	"union:":          Union,
 	"uniqueString":    UniqueString,
 	"uri":             Uri,
+	"coalesce":        Coalesce,
+	"equals":          Equals,
+	"greater":         Greater,
+	"greaterOrEquals": GreaterOrEquals,
+	"less":            Less,
+	"lessOrEquals":    LessOrEquals,
 }
 
 func Evaluate(deploymentProvider DeploymentData, name string, args ...interface{}) interface{} {
diff --git a/pkg/scanners/azure/functions/greater.go b/pkg/scanners/azure/functions/greater.go
new file mode 100644
index 000000000..24bf79834
--- /dev/null
+++ b/pkg/scanners/azure/functions/greater.go
@@ -0,0 +1,47 @@
+package functions
+
+func Greater(args ...interface{}) interface{} {
+
+	if len(args) != 2 {
+		return false
+	}
+
+	switch arg0 := args[0].(type) {
+	case int:
+		arg1, ok := args[1].(int)
+		if ok {
+			return arg0 > arg1
+		}
+	case string:
+		arg1, ok := args[1].(string)
+		if ok {
+			return arg0 > arg1
+		}
+	}
+
+	return false
+}
+
+func GreaterOrEquals(args ...interface{}) interface{} {
+
+	if len(args) != 2 {
+		return false
+	}
+
+	switch arg0 := args[0].(type) {
+	case nil:
+		return args[1] == nil
+	case int:
+		arg1, ok := args[1].(int)
+		if ok {
+			return arg0 >= arg1
+		}
+	case string:
+		arg1, ok := args[1].(string)
+		if ok {
+			return arg0 >= arg1
+		}
+	}
+
+	return false
+}
diff --git a/pkg/scanners/azure/functions/greater_test.go b/pkg/scanners/azure/functions/greater_test.go
new file mode 100644
index 000000000..8d3e1b21b
--- /dev/null
+++ b/pkg/scanners/azure/functions/greater_test.go
@@ -0,0 +1,119 @@
+package functions
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Greater(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+
+		{
+			name: "greater with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "greater with nil and nil",
+			args: []interface{}{
+				nil,
+				nil,
+			},
+			expected: false,
+		},
+		{
+			name: "greater with string and string",
+			args: []interface{}{
+				"test",
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "greater with string and int",
+			args: []interface{}{
+				"test",
+				1,
+			},
+			expected: false,
+		},
+		{
+			name: "greater with int and int",
+			args: []interface{}{
+				1,
+				1,
+			},
+			expected: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := Greater(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}
+
+func Test_GreaterThanOrEqual(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+
+		{
+			name: "greater with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "greater with nil and nil",
+			args: []interface{}{
+				nil,
+				nil,
+			},
+			expected: true,
+		},
+		{
+			name: "greater with string and string",
+			args: []interface{}{
+				"test",
+				"test",
+			},
+			expected: true,
+		},
+		{
+			name: "greater with string and int",
+			args: []interface{}{
+				"test",
+				1,
+			},
+			expected: false,
+		},
+		{
+			name: "greater with int and int",
+			args: []interface{}{
+				1,
+				1,
+			},
+			expected: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := GreaterOrEquals(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}
diff --git a/pkg/scanners/azure/functions/less.go b/pkg/scanners/azure/functions/less.go
new file mode 100644
index 000000000..e25b3662c
--- /dev/null
+++ b/pkg/scanners/azure/functions/less.go
@@ -0,0 +1,47 @@
+package functions
+
+func Less(args ...interface{}) interface{} {
+
+	if len(args) != 2 {
+		return false
+	}
+
+	switch arg0 := args[0].(type) {
+	case int:
+		arg1, ok := args[1].(int)
+		if ok {
+			return arg0 < arg1
+		}
+	case string:
+		arg1, ok := args[1].(string)
+		if ok {
+			return arg0 < arg1
+		}
+	}
+
+	return false
+}
+
+func LessOrEquals(args ...interface{}) interface{} {
+
+	if len(args) != 2 {
+		return false
+	}
+
+	switch arg0 := args[0].(type) {
+	case nil:
+		return args[1] == nil
+	case int:
+		arg1, ok := args[1].(int)
+		if ok {
+			return arg0 <= arg1
+		}
+	case string:
+		arg1, ok := args[1].(string)
+		if ok {
+			return arg0 <= arg1
+		}
+	}
+
+	return false
+}
diff --git a/pkg/scanners/azure/functions/less_test.go b/pkg/scanners/azure/functions/less_test.go
new file mode 100644
index 000000000..706ee89db
--- /dev/null
+++ b/pkg/scanners/azure/functions/less_test.go
@@ -0,0 +1,119 @@
+package functions
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Less(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+
+		{
+			name: "less with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "less with nil and nil",
+			args: []interface{}{
+				nil,
+				nil,
+			},
+			expected: false,
+		},
+		{
+			name: "less with string and string",
+			args: []interface{}{
+				"test",
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "less with string and int",
+			args: []interface{}{
+				"test",
+				1,
+			},
+			expected: false,
+		},
+		{
+			name: "less with int and int",
+			args: []interface{}{
+				1,
+				1,
+			},
+			expected: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := Less(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}
+
+func Test_LessThanOrEqual(t *testing.T) {
+	tests := []struct {
+		name     string
+		args     []interface{}
+		expected interface{}
+	}{
+
+		{
+			name: "less with nil and string",
+			args: []interface{}{
+				nil,
+				"test",
+			},
+			expected: false,
+		},
+		{
+			name: "less with nil and nil",
+			args: []interface{}{
+				nil,
+				nil,
+			},
+			expected: true,
+		},
+		{
+			name: "less with string and string",
+			args: []interface{}{
+				"test",
+				"test",
+			},
+			expected: true,
+		},
+		{
+			name: "less with string and int",
+			args: []interface{}{
+				"test",
+				1,
+			},
+			expected: false,
+		},
+		{
+			name: "less with int and int",
+			args: []interface{}{
+				1,
+				1,
+			},
+			expected: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := LessOrEquals(tt.args...)
+			assert.Equal(t, tt.expected, actual)
+		})
+	}
+}