fix: make stock trading stub explicit with demo data (#96)

* fix: make stock trading stub explicit with demo data instead of silent zeros

CheckPrice() previously returned 0,0,error when prices weren't seeded,
giving users no data and no indication the example was a stub. Now it
seeds a realistic AAPL-like opening price (182.50) on first call and
applies a +0.10 tick per call so the full buy/sell decision path is
exercisable immediately.

Prominent [DEMO STUB] comments replace the vague "Placeholder" comments
throughout so users know exactly what to replace for production use.
Removed now-unused imports (encoding/json, fmt, net/http) from the
embedded GoCode string.

Closes #73

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: resolve gocritic sloppyReassign lint error in integration handler

Replace err re-assignment with short variable declaration in
handlers/integration.go to satisfy golangci-lint pre-push hook.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: support dot-notation in resolveParamValue for integration step references (#108)

* Initial plan

* fix: support dot-notation in resolveParamValue for step result references

Co-authored-by: intel352 <77607+intel352@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: intel352 <77607+intel352@users.noreply.github.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: intel352 <77607+intel352@users.noreply.github.com>

Author: 3 people

ai/examples/stock_trading.go

@@ -42,12 +42,14 @@ Components:
 			Interface:   "modular.Module",
 			GoCode: `package module
 
+// [DEMO STUB] Replace this entire file with a real stock API integration.
+// The CheckPrice method below returns synthetic demo data.
+// In production, call a real API (e.g. Alpha Vantage, Polygon.io) and
+// parse the JSON response to get live prices.
+
 import (
 	"context"
-	"encoding/json"
-	"fmt"
 	"math"
-	"net/http"
 	"sync"
 
 	"github.com/GoCodeAlone/modular"
@@ -81,14 +83,22 @@ func (s *StockPriceChecker) Init(app modular.Application) error {
 }
 
 func (s *StockPriceChecker) CheckPrice(ctx context.Context) (currentPrice float64, pctChange float64, err error) {
-	// Placeholder: In production, call real stock API
-	s.mu.RLock()
-	defer s.mu.RUnlock()
+	// [DEMO STUB] This is example/demonstration code only.
+	// In production, replace this method body with a real stock API call,
+	// e.g. Alpha Vantage: GET /query?function=GLOBAL_QUOTE&symbol=AAPL&apikey=YOUR_KEY
+	// For now, synthetic demo prices are returned so the workflow exercises the full decision path.
+	s.mu.Lock()
+	defer s.mu.Unlock()
 
 	if s.openPrice == 0 {
-		return 0, 0, fmt.Errorf("opening price not set")
+		// Seed with a realistic demo opening price so callers always get usable data.
+		s.openPrice = 182.50 // [DEMO] hardcoded AAPL-like opening price
+		s.lastPrice = 182.50
 	}
 
+	// Simulate a small price tick so repeated calls show movement.
+	s.lastPrice += 0.10 // [DEMO] synthetic +0.10 tick per call
+
 	pctChange = ((s.lastPrice - s.openPrice) / s.openPrice) * 100
 	return s.lastPrice, pctChange, nil
 }
@@ -175,7 +185,8 @@ func (t *TradeExecutor) Execute(ctx context.Context, order TradeOrder) (*TradeRe
 	t.logger.Info(fmt.Sprintf("Executing %s order for %s: qty=%d price=%.2f",
 		order.Action, order.Symbol, order.Quantity, order.Price))
 
-	// Placeholder: In production, call brokerage API
+	// [DEMO STUB] Returns a simulated order confirmation.
+	// In production, replace this with a real brokerage API call (e.g. Alpaca, TD Ameritrade).
 	return &TradeResult{
 		OrderID:   fmt.Sprintf("ORD-%d", time.Now().UnixNano()),
 		Status:    "executed",

handlers/integration.go

@@ -354,17 +354,35 @@ func ensureConnectorConnected(ctx context.Context, connector module.IntegrationC
 }
 
 // resolveParamValue resolves a single input value, substituting step result references where applicable.
-// References use the ${varName} syntax. If the variable is not found, the original value is returned.
+// References use the ${varName} syntax. Dot-notation is supported: ${step1.value} looks up results["step1"]
+// and then retrieves the "value" key from the resulting map. If the variable is not found, the original value is returned.
 func resolveParamValue(v any, results map[string]any) any {
 	strVal, ok := v.(string)
 	if !ok || len(strVal) <= 3 || strVal[0:2] != "${" || strVal[len(strVal)-1] != '}' {
 		return v
 	}
 	// Extract the variable name, e.g., ${step1.value} -> step1.value
 	varName := strVal[2 : len(strVal)-1]
+	// Fast path: exact match in results
 	if result, found := results[varName]; found {
 		return result
 	}
+	// Dot-notation path: split on "." and traverse nested maps
+	parts := strings.SplitN(varName, ".", 2)
+	if len(parts) != 2 {
+		return v
+	}
+	stepResult, found := results[parts[0]]
+	if !found {
+		return v
+	}
+	nested, ok := stepResult.(map[string]any)
+	if !ok {
+		return v
+	}
+	if val, found := nested[parts[1]]; found {
+		return val
+	}
 	return v
 }
 

handlers/integration_handler_test.go

@@ -489,3 +489,63 @@ func TestExecuteStepWithRetry_ExhaustedRetries(t *testing.T) {
 		t.Fatal("expected error after exhausted retries")
 	}
 }
+
+func TestResolveParamValue_PlainValue(t *testing.T) {
+	results := map[string]any{"step1": map[string]any{"value": "hello"}}
+	got := resolveParamValue(42, results)
+	if got != 42 {
+		t.Errorf("expected 42, got %v", got)
+	}
+}
+
+func TestResolveParamValue_ExactMatch(t *testing.T) {
+	results := map[string]any{"step1": "direct"}
+	got := resolveParamValue("${step1}", results)
+	if got != "direct" {
+		t.Errorf("expected 'direct', got %v", got)
+	}
+}
+
+func TestResolveParamValue_DotNotation(t *testing.T) {
+	results := map[string]any{
+		"step1": map[string]any{"value": "resolved"},
+	}
+	got := resolveParamValue("${step1.value}", results)
+	if got != "resolved" {
+		t.Errorf("expected 'resolved', got %v", got)
+	}
+}
+
+func TestResolveParamValue_DotNotation_MissingKey(t *testing.T) {
+	results := map[string]any{
+		"step1": map[string]any{"other": "x"},
+	}
+	got := resolveParamValue("${step1.value}", results)
+	if got != "${step1.value}" {
+		t.Errorf("expected original string, got %v", got)
+	}
+}
+
+func TestResolveParamValue_DotNotation_NonMapResult(t *testing.T) {
+	results := map[string]any{"step1": "not-a-map"}
+	got := resolveParamValue("${step1.value}", results)
+	if got != "${step1.value}" {
+		t.Errorf("expected original string when step result is not a map, got %v", got)
+	}
+}
+
+func TestResolveParamValue_DotNotation_MissingStep(t *testing.T) {
+	results := map[string]any{}
+	got := resolveParamValue("${step1.value}", results)
+	if got != "${step1.value}" {
+		t.Errorf("expected original string when step not found, got %v", got)
+	}
+}
+
+func TestResolveParamValue_NotAReference(t *testing.T) {
+	results := map[string]any{"foo": "bar"}
+	got := resolveParamValue("just-a-string", results)
+	if got != "just-a-string" {
+		t.Errorf("expected 'just-a-string', got %v", got)
+	}
+}