fix(ttx): remove context.Context field from Transaction struct

Transaction stored a context.Context captured once at construction,
so methods reached for t.Context instead of taking a context from
their caller. A transaction rebuilt via NewTransactionFromBytes in a
different view kept the originating view's context, and
htlc.Transaction.Lock already accepted ctx but silently used t.Context
instead, dropping the caller's deadline/cancellation/tracing context.

Bytes, Issue, Transfer, Redeem, Upgrade, Outputs, and Inputs now take
ctx explicitly, threaded through every call site in token/ and
integration/.

Also enables the containedctx linter and suppresses the pattern's
remaining, reviewed occurrences (long-lived service/worker lifecycles,
a per-event struct, session-wrapper convenience defaults, and a test
fake) with a justification comment each.

Fixes #2178
Fixes #2179

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Angelo De Caro <adc@zurich.ibm.com>

Author: adecaro

.golangci.yml

@@ -1,6 +1,7 @@
 version: "2"
 linters:
   enable:
+    - containedctx
     - asasalint # Check for pass []any as any in variadic func(...any).
     - canonicalheader # Canonicalheader checks whether net/http.Header uses canonical header. [auto-fix]
     - copyloopvar # A linter detects places where loop variables are copied. [fast, auto-fix]

docs/token_sdk_usage.md

@@ -56,7 +56,7 @@ if err != nil {
 // 3. Issue Tokens
 // Use the issuer wallet to issue 'quantity' of 'tokenType' to 'recipient'.
 wallet := ttx.GetIssuerWallet(context, issuerWalletID)
-err = tx.Issue(wallet, recipient, tokenType, quantity)
+err = tx.Issue(context.Context(), wallet, recipient, tokenType, quantity)
 if err != nil {
     return nil, err
 }
@@ -99,6 +99,7 @@ if err != nil {
 // Sender wallet is used to select input tokens.
 senderWallet := ttx.GetWallet(context, senderWalletID)
 err = tx.Transfer(
+    context.Context(),
     senderWallet,
     tokenType,
     []uint64{amount},
@@ -147,6 +148,7 @@ if err != nil {
 // If needed, also pin the issuer signing key expected by public parameters.
 senderWallet := ttx.GetWallet(context, senderWalletID)
 err = tx.Redeem(
+    context.Context(),
     senderWallet,
     tokenType,
     amount,
@@ -195,7 +197,7 @@ if err != nil {
 
 // 3. Add Alice's Transfer
 senderWallet := ttx.GetWallet(context, aliceWallet)
-err = tx.Transfer(senderWallet, aliceTokenType, []uint64{aliceAmount}, []view.Identity{other})
+err = tx.Transfer(context.Context(), senderWallet, aliceTokenType, []uint64{aliceAmount}, []view.Identity{other})
 if err != nil {
     return nil, err
 }
@@ -239,7 +241,7 @@ if err != nil {
 
 // 3. Add Bob's Transfer
 bobWallet := ttx.MyWalletFromTx(context, tx)
-err = tx.Transfer(bobWallet, action.Type, []uint64{action.Amount}, []view.Identity{action.Recipient})
+err = tx.Transfer(context.Context(), bobWallet, action.Type, []uint64{action.Amount}, []view.Identity{action.Recipient})
 if err != nil {
     return nil, err
 }
@@ -343,8 +345,8 @@ if err != nil {
 Uses an **Initiator-Responder Inversion** pattern. The user requests a withdrawal, and the Issuer (responder) becomes the initiator of the Token Transaction to issue the tokens.
 
 ### Multisig ([`multisig.go`](../integration/token/fungible/views/multisig.go))
-*   **Lock**: `multisig.Wrap(tx).Lock(...)`
-*   **Spend**: `multisig.Wrap(tx).Spend(...)`. Requires `multisig.Wallet` to list co-owned tokens.
+*   **Lock**: `multisig.Wrap(tx).Lock(ctx, ...)`
+*   **Spend**: `multisig.Wrap(tx).Spend(ctx, ...)`. Requires `multisig.Wallet` to list co-owned tokens.
 
 ---
 

docs/upgradability.md

@@ -74,6 +74,7 @@ tx, err := ttx.NewTransaction(context, nil, ttx.WithTMSID(upgradeRequest.TMSID))
 
 // The Upgrade call consumes old tokens and issues new ones in one atomic step
 err = tx.Upgrade(
+    context.Context(),
     issuerWallet,
     upgradeRequest.RecipientIdentity,
     upgradeRequest.Challenge,

integration/token/dvp/views/auditor.go

@@ -24,7 +24,7 @@ func (a *AuditView) Call(context view.Context) (any, error) {
 	// Validate
 	auditor, err := ttx.NewAuditor(context, w)
 	assert.NoError(err, "failed to get auditor instance")
-	assert.NoError(auditor.Validate(tx), "failed auditing verification")
+	assert.NoError(auditor.Validate(context.Context(), tx), "failed auditing verification")
 
 	return context.RunView(ttx.NewAuditApproveView(w, tx))
 }

integration/token/dvp/views/buyer.go

@@ -32,7 +32,7 @@ func (b *BuyHouseView) Call(context view.Context) (any, error) {
 
 	// check transaction, it must contain the house transfer
 	nfttx := nfttx.Wrap(tx)
-	outputs, err := nfttx.Outputs()
+	outputs, err := nfttx.Outputs(context.Context())
 	assert.NoError(err, "failed getting outputs")
 	assert.NoError(outputs.Validate(), "failed validating outputs")
 	assert.True(outputs.Count() == 1, "the transaction must contain one output")
@@ -54,6 +54,7 @@ func (b *BuyHouseView) Call(context view.Context) (any, error) {
 
 	// Append the cash transfer to the transaction
 	err = tx.Transfer(
+		context.Context(),
 		ttx.MyWalletFromTx(context, tx),
 		action.Type,
 		[]uint64{action.Amount},

integration/token/dvp/views/cash/accept.go

@@ -30,7 +30,7 @@ func (a *AcceptCashView) Call(context view.Context) (any, error) {
 	// The recipient can perform any check on the transaction as required by the business process
 	// In particular, here, the recipient checks that the transaction contains at least one output, and
 	// that there is at least one output that names the recipient. (The recipient is receiving something.
-	outputs, err := tx.Outputs()
+	outputs, err := tx.Outputs(context.Context())
 	assert.NoError(err, "failed getting outputs")
 	assert.True(outputs.Count() > 0)
 	assert.True(outputs.ByRecipient(id).Count() > 0)

integration/token/dvp/views/cash/issue.go

@@ -55,6 +55,7 @@ func (p *IssueCashView) Call(context view.Context) (any, error) {
 	wallet := ttx.GetIssuerWallet(context, p.IssuerWallet)
 	assert.NotNil(wallet, "issuer wallet [%s] not found", p.IssuerWallet)
 	err = tx.Issue(
+		context.Context(),
 		wallet,
 		recipient,
 		p.TokenType,

integration/token/dvp/views/house/accept.go

@@ -29,7 +29,7 @@ func (a *AcceptHouseView) Call(context view.Context) (any, error) {
 	// The recipient can perform any check on the transaction as required by the business process
 	// In particular, here, the recipient checks that the transaction contains one output that names the recipient.
 	// (The recipient is receiving something)
-	outputs, err := tx.Outputs()
+	outputs, err := tx.Outputs(context.Context())
 	assert.NoError(err, "failed getting outputs")
 	assert.NoError(outputs.Validate(), "failed validating outputs")
 	assert.True(outputs.Count() == 1, "the transaction must contain one output")

integration/token/dvp/views/house/issue.go

@@ -62,7 +62,7 @@ func (p *IssueHouseView) Call(context view.Context) (any, error) {
 	uniqueID, err := uniqueness.GetService(context).ComputeID(context.Context(), h.Address)
 	assert.NoError(err, "failed computing unique ID")
 
-	err = tx.Issue(wallet, h, recipient, nfttx.WithUniqueID(uniqueID))
+	err = tx.Issue(context.Context(), wallet, h, recipient, nfttx.WithUniqueID(uniqueID))
 	assert.NoError(err, "failed adding new issued token")
 
 	// The issuer is ready to collect all the required signatures.

integration/token/dvp/views/seller.go

@@ -99,7 +99,7 @@ func (d *SellHouseView) prepareHouseTransfer(context view.Context, tx *ttx.Trans
 	assert.NotNil(wallet, "failed getting default wallet")
 
 	// Transfer ownership of the house to the buyer
-	assert.NoError(nfttx.Wrap(tx).Transfer(wallet, house, buyer), "failed transferring house")
+	assert.NoError(nfttx.Wrap(tx).Transfer(context.Context(), wallet, house, buyer), "failed transferring house")
 
 	return tx, house, nil
 }