[processor/transform] Report all parsing errors (#24245)

**Description:**

Follow up from
#23840
to report all errors that occur during parsing. The error isn't pretty,
but this way users know all syntax errors in their OTTL statements up
front.

I played around with trying to format this to make it more readable, but
wasn't able to come up with anything that was satisfactory.

Example config and resulting error:

```yaml
processors:
  transform:
    trace_statements:
      - context: span
        statements: 
        - ParseJSON("...")
        - false
        - set[[]]
    metric_statements:
      - context: datapoint
        statements: 
        - set(attributes, attributes)
        - true
        - set(
```

```
Error: invalid configuration: processors::transform: unable to parse OTTL statement "ParseJSON(\"...\")": editor names must start with a lowercase letter but got 'ParseJSON'; unable to parse OTTL statement "0": statement has invalid syntax: 1:1: unexpected token "0"; unable to parse OTTL statement "set[[]]": statement has invalid syntax: 1:4: unexpected token "[" (expected "(" (Value ("," Value)*)? ")" Key*); unable to parse OTTL statement "1": statement has invalid syntax: 1:1: unexpected token "1"; unable to parse OTTL statement "set(": statement has invalid syntax: 1:5: unexpected token "<EOF>" (expected ")" Key*)
```

I aggregated the errors both in the `Config` struct and on processor
startup, but realistically are highly unlikely to get an error from the
parser on startup because we've already validated the statements. I
updated it just so we're consistent between validating the config and
reporting errors from the OTTL parser.

---------

Co-authored-by: Evan Bradley <[email protected]>

.chloggen/tp-report-all-parsing-errors.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: processor/transform
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Report all errors from parsing OTTL statements
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [24245]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

processor/transformprocessor/config.go

@@ -5,6 +5,7 @@ package transformprocessor // import "github.com/open-telemetry/opentelemetry-co
 
 import (
 	"go.opentelemetry.io/collector/component"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -31,6 +32,8 @@ type Config struct {
 var _ component.Config = (*Config)(nil)
 
 func (c *Config) Validate() error {
+	var errors error
+
 	if len(c.TraceStatements) > 0 {
 		pc, err := common.NewTraceParserCollection(component.TelemetrySettings{Logger: zap.NewNop()}, common.WithSpanParser(traces.SpanFunctions()), common.WithSpanEventParser(traces.SpanEventFunctions()))
 		if err != nil {
@@ -39,7 +42,7 @@ func (c *Config) Validate() error {
 		for _, cs := range c.TraceStatements {
 			_, err = pc.ParseContextStatements(cs)
 			if err != nil {
-				return err
+				errors = multierr.Append(errors, err)
 			}
 		}
 	}
@@ -50,9 +53,9 @@ func (c *Config) Validate() error {
 			return err
 		}
 		for _, cs := range c.MetricStatements {
-			_, err = pc.ParseContextStatements(cs)
+			_, err := pc.ParseContextStatements(cs)
 			if err != nil {
-				return err
+				errors = multierr.Append(errors, err)
 			}
 		}
 	}
@@ -65,10 +68,10 @@ func (c *Config) Validate() error {
 		for _, cs := range c.LogStatements {
 			_, err = pc.ParseContextStatements(cs)
 			if err != nil {
-				return err
+				errors = multierr.Append(errors, err)
 			}
 		}
 	}
 
-	return nil
+	return errors
 }

processor/transformprocessor/config_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/confmap/confmaptest"
+	"go.uber.org/multierr"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/transformprocessor/internal/common"
@@ -22,6 +23,7 @@ func TestLoadConfig(t *testing.T) {
 	tests := []struct {
 		id       component.ID
 		expected component.Config
+		errorLen int
 	}{
 		{
 			id: component.NewIDWithName(metadata.Type, ""),
@@ -108,6 +110,10 @@ func TestLoadConfig(t *testing.T) {
 		{
 			id: component.NewIDWithName(metadata.Type, "unknown_function_log"),
 		},
+		{
+			id:       component.NewIDWithName(metadata.Type, "bad_syntax_multi_signal"),
+			errorLen: 3,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.id.String(), func(t *testing.T) {
@@ -122,7 +128,13 @@ func TestLoadConfig(t *testing.T) {
 			assert.NoError(t, component.UnmarshalConfig(sub, cfg))
 
 			if tt.expected == nil {
-				assert.Error(t, component.ValidateConfig(cfg))
+				err = component.ValidateConfig(cfg)
+				assert.Error(t, err)
+
+				if tt.errorLen > 0 {
+					assert.Equal(t, tt.errorLen, len(multierr.Errors(err)))
+				}
+
 				return
 			}
 			assert.NoError(t, component.ValidateConfig(cfg))

processor/transformprocessor/go.mod

@@ -10,6 +10,7 @@ require (
 	go.opentelemetry.io/collector/consumer v0.81.0
 	go.opentelemetry.io/collector/pdata v1.0.0-rcv0013
 	go.opentelemetry.io/collector/processor v0.81.0
+	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.24.0
 )
 
@@ -39,7 +40,6 @@ require (
 	go.opentelemetry.io/otel/metric v1.16.0 // indirect
 	go.opentelemetry.io/otel/trace v1.16.0 // indirect
 	go.uber.org/atomic v1.10.0 // indirect
-	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/exp v0.0.0-20230510235704-dd950f8aeaea // indirect
 	golang.org/x/net v0.12.0 // indirect
 	golang.org/x/sys v0.10.0 // indirect

processor/transformprocessor/internal/logs/processor.go

@@ -9,6 +9,7 @@ import (
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/pdata/plog"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -27,14 +28,19 @@ func NewProcessor(contextStatements []common.ContextStatements, errorMode ottl.E
 	}
 
 	contexts := make([]consumer.Logs, len(contextStatements))
+	var errors error
 	for i, cs := range contextStatements {
 		context, err := pc.ParseContextStatements(cs)
 		if err != nil {
-			return nil, err
+			errors = multierr.Append(errors, err)
 		}
 		contexts[i] = context
 	}
 
+	if errors != nil {
+		return nil, errors
+	}
+
 	return &Processor{
 		contexts: contexts,
 		logger:   settings.Logger,

processor/transformprocessor/internal/metrics/processor.go

@@ -9,6 +9,7 @@ import (
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -27,14 +28,19 @@ func NewProcessor(contextStatements []common.ContextStatements, errorMode ottl.E
 	}
 
 	contexts := make([]consumer.Metrics, len(contextStatements))
+	var errors error
 	for i, cs := range contextStatements {
 		context, err := pc.ParseContextStatements(cs)
 		if err != nil {
-			return nil, err
+			errors = multierr.Append(errors, err)
 		}
 		contexts[i] = context
 	}
 
+	if errors != nil {
+		return nil, errors
+	}
+
 	return &Processor{
 		contexts: contexts,
 		logger:   settings.Logger,

processor/transformprocessor/internal/traces/processor.go

@@ -9,6 +9,7 @@ import (
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/consumer"
 	"go.opentelemetry.io/collector/pdata/ptrace"
+	"go.uber.org/multierr"
 	"go.uber.org/zap"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -27,14 +28,19 @@ func NewProcessor(contextStatements []common.ContextStatements, errorMode ottl.E
 	}
 
 	contexts := make([]consumer.Traces, len(contextStatements))
+	var errors error
 	for i, cs := range contextStatements {
 		context, err := pc.ParseContextStatements(cs)
 		if err != nil {
-			return nil, err
+			errors = multierr.Append(errors, err)
 		}
 		contexts[i] = context
 	}
 
+	if errors != nil {
+		return nil, errors
+	}
+
 	return &Processor{
 		contexts: contexts,
 		logger:   settings.Logger,

processor/transformprocessor/testdata/config.yaml

@@ -52,6 +52,23 @@ transform/bad_syntax_trace:
         - set(name, "bear" where attributes["http.path"] == "/animal"
         - keep_keys(attributes, ["http.method", "http.path"])
 
+transform/bad_syntax_multi_signal:
+  trace_statements:
+    - context: span
+      statements:
+        - set(name, "bear" where attributes["http.path"] == "/animal"
+        - keep_keys(attributes, ["http.method", "http.path"])
+  metric_statements:
+    - context: datapoint
+      statements:
+        - set(name, "bear" where attributes["http.path"] == "/animal"
+        - keep_keys(attributes, ["http.method", "http.path"])
+  log_statements:
+    - context: log
+      statements:
+        - set(body, "bear" where attributes["http.path"] == "/animal"
+        - keep_keys(attributes, ["http.method", "http.path"])
+
 transform/unknown_function_log:
   log_statements:
     - context: log