feat: transformation conditions

.gitignore

@@ -27,4 +27,3 @@ venv
 .cache
 # Binaries
 cmd/greenmask/greenmask
-pkg/toolkit/test/test

docs/built_in_transformers/advanced_transformers/custom_functions/index.md

@@ -1,14 +1,22 @@
 # Template custom functions
 
-Within Greenmask, custom functions play a crucial role, providing a wide array of options for implementing diverse logic. Under the hood, the custom functions are based on the [sprig Go's template functions](https://masterminds.github.io/sprig/). Greenmask enhances this capability by introducing additional functions and transformation functions. These extensions mirror the logic found in the [standard transformers](../../standard_transformers/index.md) but offer you the flexibility to implement intricate and comprehensive logic tailored to your specific needs.
+Within Greenmask, custom functions play a crucial role, providing a wide array of options for implementing diverse
+logic. Under the hood, the custom functions are based on
+the [sprig Go's template functions](https://masterminds.github.io/sprig/). Greenmask enhances this capability by
+introducing additional functions and transformation functions. These extensions mirror the logic found in
+the [standard transformers](../../standard_transformers/index.md) but offer you the flexibility to implement intricate
+and comprehensive logic tailored to your specific needs.
 
 Currently, you can use template custom functions for the [advanced transformers](../index.md):
 
 * [Json](../json.md)
 * [Template](../template.md)
 * [TemplateRecord](../template_record.md)
 
+and for the [Transformation condition feature](../../transformation_condition.md) as well.
+
 Custom functions are arbitrarily divided into 2 groups:
 
-- [Core functions](core_functions.md) — custom functions that vary in purpose and include PostgreSQL driver, JSON output, testing, and transformation functions.
+- [Core functions](core_functions.md) — custom functions that vary in purpose and include PostgreSQL driver, JSON
+  output, testing, and transformation functions.
 - [Faker functions](faker_function.md) — custom function of a *faker* type which generate synthetic data.

docs/built_in_transformers/advanced_transformers/index.md

@@ -5,6 +5,6 @@ Advanced transformers are modifiable anonymization methods that users can adjust
 Below you can find an index of all advanced transformers currently available in Greenmask.
 
 1. [Json](json.md) — changes a JSON content by using `delete` and `set` operations.
-1. [Template](template.md) — executes a Go template of your choice and applies the result to a specified column.
-1. [TemplateRecord](template_record.md) — modifies records by using a Go template of your choice and applies the changes via the PostgreSQL
+2. [Template](template.md) — executes a Go template of your choice and applies the result to a specified column.
+3. [TemplateRecord](template_record.md) — modifies records by using a Go template of your choice and applies the changes via the PostgreSQL
 driver.

docs/built_in_transformers/transformation_condition.md

@@ -0,0 +1,160 @@
+# Transformation Condition
+
+## Description
+
+The transformation condition feature allows you to execute a defined transformation only if a specified condition is
+met.
+The condition must be defined as a boolean expression that evaluates to `true` or `false`. Greenmask uses
+[expr-lang/expr](https://github.com/expr-lang/expr) under the hood. You can use all functions and syntax provided by the
+`expr` library.
+
+You can use the same functions that are described in
+the [built-in transformers](/docs/built_in_transformers/advanced_transformers/custom_functions/index.md)
+
+The transformers are executed one by one - this helps you create complex transformation pipelines. For instance
+depending on value chosen in the previous transformer, you can decide to execute the next transformer or not.
+
+## Record descriptors
+
+To improve the user experience, Greenmask offers special namespaces for accessing values in different formats: either
+the driver-encoded value in its real type or as a raw string.
+
+- **`record`**: This namespace provides the record value in its actual type.
+- **`raw_record`**: This namespace provides the record value as a string.
+
+You can access a specific column’s value using `record.column_name` for the real type or `raw_record.column_name` for
+the raw string value.
+
+!!! warning
+
+    A record may always be modified by previous transformers before the condition is evaluated. This means Greenmask does
+    not retain the original record value and instead provides the current modified value for condition evaluation.
+
+## Null values condition
+
+To check if the value is null, you can use `null` value for the comparisson. This operation works compatibly
+with SQL operator `IS NULL` or `IS NOT NULL`.
+
+```text title="Is null cond example"
+record.accountnumber == null && record.date > now()
+```
+
+```text title="Is not null cond example"
+record.accountnumber != null && record.date <= now()
+```
+
+## Expression scope
+
+Expression scope can be on table or specific transformer. If you define the condition on the table scope, then the
+condition will be evaluated before any transformer is executed. If you define the condition on the transformer scope,
+then the condition will be evaluated before the specified transformer is executed.
+
+```yaml title="Table scope" 
+- schema: "purchasing"
+  name: "vendor"
+  when: 'record.accountnumber == null || record.accountnumber == "ALLENSON0001"'
+  transformers:
+    - name: "RandomString"
+      params:
+        column: "accountnumber"
+        min_length: 9
+        max_length: 12
+        symbols: "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+```
+
+```yaml title="Transformer scope" 
+- schema: "purchasing"
+  name: "vendor"
+  transformers:
+    - name: "RandomString"
+      when: 'record.accountnumber != null || record.accountnumber == "ALLENSON0001"'
+      params:
+        column: "accountnumber"
+        min_length: 9
+        max_length: 12
+        symbols: "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+```
+
+## Int and float value definition
+
+It is important to create the integer or float value in the correct format. If you want to define the integer value you
+must write a number without dot (`1`, `2`, etc.). If you want to define the float value you must write a number with
+dot (`1.0`, `2.0`, etc.).
+
+!!! warning
+
+    You may see a wrong comparison result if you compare int and float, for example `1 == 1.0` will return `false`. 
+
+## Architecture
+
+Greenmask encodes the way only when evaluating the condition - this allows to optimize the performance of the
+transformation if you have a lot of conditions that uses or (`||`) or and (`&&`) operators.
+
+## Example: Chose random value and execute one of
+
+In the following example, the `RandomChoice` transformer is used to choose a random value from the list of values.
+Depending on the chosen value, the `Replace` transformer is executed to set the `activeflag` column to `true` or
+`false`.
+
+In this case the condition scope is on the transformer level.
+
+```yaml
+- schema: "purchasing"
+  name: "vendor"
+  transformers:
+    - name: "RandomChoice"
+      params:
+        column: "name"
+        values:
+          - "test1"
+          - "test2"
+
+    - name: "Replace"
+      when: 'record.name == "test1"'
+      params:
+        column: "activeflag"
+        value: "false"
+
+    - name: "Replace"
+      when: 'record.name == "test2"'
+      params:
+        column: "activeflag"
+        value: "true"
+```
+
+## Example: Do not transform specific columns
+
+In the following example, the `RandomString` transformer is executed only if the `businessentityid` column value is not
+equal to `1492` or `1`.
+
+```yaml
+  - schema: "purchasing"
+    name: "vendor"
+    when: '!(record.businessentityid | has([1492, 1]))'
+    transformers:
+      - name: "RandomString"
+        params:
+          column: "accountnumber"
+          min_length: 9
+          max_length: 12
+          symbols: "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+```
+
+## Example: Check the json attribute value
+
+In the following example, the `RandomString` transformer is executed only if the `a` attribute in the `json_data` column
+is equal to `1`.
+
+```yaml
+- schema: "public"
+  name: "jsondata"
+  when: 'raw_record.json_data | jsonGet("a") == 1'
+  transformers:
+    - name: "RandomString"
+      params:
+        column: "accountnumber"
+        min_length: 9
+        max_length: 12
+        symbols: "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+```
+

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/Masterminds/sprig/v3 v3.3.0
 	github.com/aws/aws-sdk-go v1.55.5
 	github.com/dchest/siphash v1.2.3
+	github.com/expr-lang/expr v1.16.7
 	github.com/ggwhite/go-masker v1.1.0
 	github.com/go-faker/faker/v4 v4.5.0
 	github.com/google/uuid v1.6.0

go.sum

@@ -16,6 +16,8 @@ github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dchest/siphash v1.2.3 h1:QXwFc8cFOR2dSa/gE6o/HokBMWtLUaNDVd+22aKHeEA=
 github.com/dchest/siphash v1.2.3/go.mod h1:0NvQU092bT0ipiFN++/rXm69QG9tVxLAlQHIXMPAkHc=
+github.com/expr-lang/expr v1.16.7 h1:gCIiHt5ODA0xIaDbD0DPKyZpM9Drph3b3lolYAYq2Kw=
+github.com/expr-lang/expr v1.16.7/go.mod h1:8/vRC7+7HBzESEqt5kKpYXxrxkr31SaO8r40VO/1IT4=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=

internal/db/postgres/cmd/validate.go

@@ -130,9 +130,15 @@ func (v *Validate) Run(ctx context.Context) (int, error) {
 		return nonZeroExitCode, fmt.Errorf("unable to build runtime context: %w", err)
 	}
 
-	if err = v.printValidationWarnings(); err != nil {
+	err = toolkit.PrintValidationWarnings(
+		v.context.Warnings, v.config.Validate.ResolvedWarnings, v.config.Validate.Warnings,
+	)
+	if err != nil {
 		return nonZeroExitCode, err
 	}
+	if v.context.IsFatal() {
+		return nonZeroExitCode, fmt.Errorf("fatal validation error")
+	}
 
 	if err = v.diffWithPreviousSchema(ctx); err != nil {
 		return nonZeroExitCode, err
@@ -280,34 +286,6 @@ func (v *Validate) createDocument(ctx context.Context, t *entries.Table) (valida
 	return doc, nil
 }
 
-func (v *Validate) printValidationWarnings() error {
-	// TODO: Implement warnings hook, such as logging and HTTP sender
-	for _, w := range v.context.Warnings {
-		w.MakeHash()
-		if idx := slices.Index(v.config.Validate.ResolvedWarnings, w.Hash); idx != -1 {
-			log.Debug().Str("hash", w.Hash).Msg("resolved warning has been excluded")
-			if w.Severity == toolkit.ErrorValidationSeverity {
-				return fmt.Errorf("warning with hash %s cannot be excluded because it is an error", w.Hash)
-			}
-			continue
-		}
-
-		if w.Severity == toolkit.ErrorValidationSeverity {
-			// The warnings with error severity must be printed anyway
-			log.Error().Any("ValidationWarning", w).Msg("")
-		} else {
-			// Print warnings with severity level lower than ErrorValidationSeverity only if requested
-			if v.config.Validate.Warnings {
-				log.Warn().Any("ValidationWarning", w).Msg("")
-			}
-		}
-	}
-	if v.context.IsFatal() {
-		return fmt.Errorf("fatal validation error")
-	}
-	return nil
-}
-
 func (v *Validate) getTablesToValidate() ([]*domains.Table, error) {
 	var tablesToValidate []*domains.Table
 	for _, tv := range v.config.Validate.Tables {

internal/db/postgres/cmd/validate_utils/json_document_test.go

@@ -15,26 +15,6 @@ import (
 	"github.com/greenmaskio/greenmask/pkg/toolkit"
 )
 
-type testTransformer struct{}
-
-func (tt *testTransformer) Init(ctx context.Context) error {
-	return nil
-}
-
-func (tt *testTransformer) Done(ctx context.Context) error {
-	return nil
-}
-
-func (tt *testTransformer) Transform(ctx context.Context, r *toolkit.Record) (*toolkit.Record, error) {
-	return nil, nil
-}
-
-func (tt *testTransformer) GetAffectedColumns() map[int]string {
-	return map[int]string{
-		1: "name",
-	}
-}
-
 func TestJsonDocument_GetAffectedColumns(t *testing.T) {
 	tab, _, _ := getTableAndRows()
 	jd := NewJsonDocument(tab, true, true)
@@ -87,6 +67,26 @@ func TestJsonDocument_GetRecords(t *testing.T) {
 	//r.SetRow(row)
 }
 
+type testTransformer struct{}
+
+func (tt *testTransformer) Init(ctx context.Context) error {
+	return nil
+}
+
+func (tt *testTransformer) Done(ctx context.Context) error {
+	return nil
+}
+
+func (tt *testTransformer) Transform(ctx context.Context, r *toolkit.Record) (*toolkit.Record, error) {
+	return nil, nil
+}
+
+func (tt *testTransformer) GetAffectedColumns() map[int]string {
+	return map[int]string{
+		1: "name",
+	}
+}
+
 func getTableAndRows() (table *entries.Table, original, transformed [][]byte) {
 
 	tableDef := `

internal/db/postgres/context/table.go

@@ -124,7 +124,7 @@ func validateAndBuildTablesConfig(
 			// InitTransformation toolkit
 			if len(tableCfg.Transformers) > 0 {
 				for _, tc := range tableCfg.Transformers {
-					transformer, initWarnings, err := initTransformer(ctx, driver, tc, registry, types)
+					transformer, initWarnings, err := initTransformer(ctx, driver, tc, registry)
 					if len(initWarnings) > 0 {
 						for _, w := range initWarnings {
 							// Enriching the tables context into meta
@@ -155,6 +155,7 @@ func validateAndBuildTablesConfig(
 func getTable(ctx context.Context, tx pgx.Tx, t *domains.Table) ([]*entries.Table, toolkit.ValidationWarnings, error) {
 	table := &entries.Table{
 		Table: &toolkit.Table{},
+		When:  t.When,
 	}
 	var warnings toolkit.ValidationWarnings
 	var tables []*entries.Table
@@ -204,6 +205,7 @@ func getTable(ctx context.Context, tx pgx.Tx, t *domains.Table) ([]*entries.Tabl
 				RootPtSchema: table.Schema,
 				RootPtName:   table.Name,
 				RootOid:      table.Oid,
+				When:         table.When,
 			}
 			if err = rows.Scan(&pt.Oid, &pt.Schema, &pt.Name); err != nil {
 				return nil, nil, fmt.Errorf("error scanning TableGetChildPatsQuery: %w", err)

internal/db/postgres/context/transformers.go

@@ -27,22 +27,21 @@ func initTransformer(
 	ctx context.Context, d *toolkit.Driver,
 	c *domains.TransformerConfig,
 	r *transformersUtils.TransformerRegistry,
-	types []*toolkit.Type,
 ) (*transformersUtils.TransformerContext, toolkit.ValidationWarnings, error) {
 	var totalWarnings toolkit.ValidationWarnings
 	td, ok := r.Get(c.Name)
 	if !ok {
 		totalWarnings = append(totalWarnings,
 			toolkit.NewValidationWarning().
 				SetMsg("transformer not found").
-				SetSeverity(toolkit.ErrorValidationSeverity).SetTrace(&toolkit.Trace{
-				SchemaName:      d.Table.Schema,
-				TableName:       d.Table.Name,
-				TransformerName: c.Name,
-			}))
+				AddMeta("SchemaName", d.Table.Schema).
+				AddMeta("TableName", d.Table.Name).
+				AddMeta("TransformerName", c.Name).
+				SetSeverity(toolkit.ErrorValidationSeverity),
+		)
 		return nil, totalWarnings, nil
 	}
-	transformer, warnings, err := td.Instance(ctx, d, c.Params, c.DynamicParams)
+	transformer, warnings, err := td.Instance(ctx, d, c.Params, c.DynamicParams, c.When)
 	if err != nil {
 		return nil, nil, fmt.Errorf("unable to init transformer: %w", err)
 	}