feat(trace): report the generated line totals of a session

app/cli/internal/trace/README.md

@@ -56,7 +56,7 @@ Which lines of a commit the AI wrote.
 |---------|---------------|-------------|--------|--------------|------------|---|---|
 | Line attribution | Each changed line of a commit is attributed to the AI or to a human, from a snapshot of each file before and after the agent edits it. An added line is AI when its content matches a line that an agent edit of the session wrote. A line that a human changed is human, also when a later agent edit keeps it. A whitespace-only change keeps the owner of the line. A removed line is AI only when an agent edit removed it. In a commit of more than one session, a line that only another session wrote or removed counts for neither side in this session's evidence (spec issue-3639). | Yes | Partial | Yes | Yes | No | No |
 | Partial commits | A commit that holds only part of the AI lines of a file credits the session with those lines. The other AI lines stay pending, and the next commit with them is credited to the session too (spec issue-3639). | Yes | Partial | Yes | Yes | No | No |
-| Generated line counts | The trace state keeps the lines that each agent edit added and removed, also the lines that never reach a commit. The evidence does not report them yet (spec issue-3639). | Yes | Partial | Yes | Yes | No | No |
+| Generated line counts | The trace state keeps the lines that each agent edit added and removed, also the lines that never reach a commit. The evidence reports the totals of the session in `ai_generated_lines_added` and `ai_generated_lines_removed`. A session with no commit sends no evidence, so it reports no totals (spec issue-3639). | Yes | Partial | Yes | Yes | No | No |
 | Shell changes attribution | Changes that the agent makes with shell commands (for example `sed`) are attributed to the AI too, not only changes made with the file tools. | Partial | Partial | Partial | Partial | No | No |
 | Net contribution | The added lines of a session are the lines that its commits added and that are still in the commit that the push sends. A line that a later commit replaced does not count, and each line counts one time. The removed lines are the removals of the session's commits, less the lines that a commit of the session wrote. The line counts of each file are the sum of its AI and human lines, and a file that the session created stays created when a later commit of the session changes it (spec issue-3639, issue 3674). | Partial | Partial | Partial | Partial | No | No |
 | Session updates | A later commit that replaces lines of a session sends the evidence of the session again at the next push, with the new numbers. A commit in no session that replaces lines of a session joins it: the commit list of the session holds the commit, and its replacing lines count as human (spec issue-3639). | Partial | Partial | Partial | Partial | No | No |

app/cli/internal/trace/attribution/enrich.go

@@ -150,6 +150,10 @@ func Enrich(sessionID string, ledgers map[string]*state.AILineAttribution, commi
 		changes.HumanLinesAdded += f.HumanLinesAdded
 		changes.HumanLinesRemoved += f.HumanLinesRemoved
 	}
+
+	// All the lines that the agent edits of the session wrote, also the ones
+	// that never reached a commit (spec issue-3639, R-011, D-011).
+	changes.AIGeneratedLinesAdded, changes.AIGeneratedLinesRemoved = self.GeneratedAdded, self.GeneratedRemoved
 }
 
 // fileSplit is the AI/human split of the changed lines of one file.

app/cli/internal/trace/attribution/enrich_test.go

@@ -189,6 +189,61 @@ func TestEnrich_Legacy(t *testing.T) {
 	})
 }
 
+func TestEnrich_GeneratedLines(t *testing.T) {
+	withGenerated := func(attr *state.AILineAttribution, added, removed int) *state.AILineAttribution {
+		attr.GeneratedAdded, attr.GeneratedRemoved = added, removed
+
+		return attr
+	}
+
+	testCases := []struct {
+		name                   string
+		ledgers                map[string]*state.AILineAttribution
+		wantAdded, wantRemoved int
+	}{
+		{
+			// The agent wrote 10 lines and removed 3. Only 2 lines reached
+			// the commit; the session still reports all of them (spec
+			// issue-3639, D-011).
+			name: "reports all the lines of the agent edits, also the ones that no commit holds",
+			ledgers: map[string]*state.AILineAttribution{
+				testSession: withGenerated(ledger(testSession, testFile, []string{"a", "b"}, nil), 10, 3),
+			},
+			wantAdded:   10,
+			wantRemoved: 3,
+		},
+		{
+			name: "does not add the lines of another session",
+			ledgers: map[string]*state.AILineAttribution{
+				testSession:  withGenerated(ledger(testSession, testFile, []string{"a", "b"}, nil), 2, 0),
+				otherSession: withGenerated(ledger(otherSession, testFile, []string{"c"}, nil), 7, 1),
+			},
+			wantAdded: 2,
+		},
+		{
+			name:    "a session with no ledger reports no lines",
+			ledgers: nil,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			changes := &aicodingsession.CodeChanges{
+				LinesAdded: 2,
+				Files:      []aicodingsession.FileChange{{Path: testFile, LinesAdded: 2}},
+			}
+			commits := []CommitLines{{SessionIDs: []string{testSession}, Files: []tracegit.FileLines{
+				{Path: testFile, Added: []string{"a", "b"}},
+			}}}
+
+			Enrich(testSession, tc.ledgers, commits, nil, changes)
+
+			assert.Equal(t, tc.wantAdded, changes.AIGeneratedLinesAdded)
+			assert.Equal(t, tc.wantRemoved, changes.AIGeneratedLinesRemoved)
+		})
+	}
+}
+
 func TestEnrich_Lines(t *testing.T) {
 	type split struct{ aiAdded, aiRemoved, humanAdded, humanRemoved int }
 

app/cli/internal/trace/e2e/checks.go

@@ -99,9 +99,7 @@ var features = map[string]Feature{
 	"Shell changes attribution": {Checks: []Check{{scenarioEditAndCommit, checkFileAttributedToAI("shell.txt")}}},
 	"Partial commits":           {Checks: []Check{{scenarioPartial, checkBothCommitsCredited}}},
 	"Line ranges":               {Checks: []Check{{scenarioEditAndCommit, checkLineRanges("greeting.txt", 3)}}},
-	"Generated line counts": {
-		NotCovered: "neither the user nor the evidence can see the generated line counts yet",
-	},
+	"Generated line counts":     {Checks: []Check{{scenarioEditAndCommit, checkGeneratedLineCounts}}},
 
 	// User experience
 	"Welcome message":         {Checks: []Check{{scenarioEditAndCommit, checkWelcomeMessage}}},
@@ -196,6 +194,23 @@ func checkFileAttributedToAI(path string) func(s *Session) error {
 	}
 }
 
+// checkGeneratedLineCounts verifies that the evidence reports the lines of
+// all the agent edits. Each net AI line came from an agent edit, so the
+// generated lines are at least the net AI lines.
+func checkGeneratedLineCounts(s *Session) error {
+	cc := evidence(s).CodeChanges
+	if cc == nil {
+		return errors.New("the evidence has no code changes")
+	}
+	if cc.AIGeneratedLinesAdded == 0 {
+		return errors.New("the evidence has no generated lines added")
+	}
+	if cc.AIGeneratedLinesAdded < cc.AILinesAdded {
+		return fmt.Errorf("%d generated lines added, fewer than the %d net AI lines added", cc.AIGeneratedLinesAdded, cc.AILinesAdded)
+	}
+	return nil
+}
+
 // hookMessage returns the first hook message of an event, or errNotCovered
 // when the harness does not report hook messages.
 func hookMessage(s *Session, event string) (*HookMessage, error) {

internal/schemavalidators/internal_schemas/aicodingsession/ai-coding-session-0.1.schema.json

@@ -170,27 +170,35 @@
         },
         "lines_added": {
           "type": "integer",
-          "description": "Total lines added"
+          "description": "Net lines added by the session's commits (AI plus human); raw diff totals if a commit is unreadable"
         },
         "lines_removed": {
           "type": "integer",
-          "description": "Total lines removed"
+          "description": "Net lines removed by the session's commits (AI plus human); raw diff totals if a commit is unreadable"
         },
         "ai_lines_added": {
           "type": "integer",
-          "description": "Lines added attributed to AI"
+          "description": "Net committed lines added, attributed to AI"
         },
         "ai_lines_removed": {
           "type": "integer",
-          "description": "Lines removed attributed to AI"
+          "description": "Net committed lines removed, attributed to AI"
         },
         "human_lines_added": {
           "type": "integer",
-          "description": "Lines added attributed to human"
+          "description": "Net committed lines added, attributed to human"
         },
         "human_lines_removed": {
           "type": "integer",
-          "description": "Lines removed attributed to human"
+          "description": "Net committed lines removed, attributed to human"
+        },
+        "ai_generated_lines_added": {
+          "type": "integer",
+          "description": "All lines added by the agent edits of the session, committed or not; not net"
+        },
+        "ai_generated_lines_removed": {
+          "type": "integer",
+          "description": "All lines removed by the agent edits of the session, committed or not; not net"
         },
         "files": {
           "type": "array",

pkg/attestation/crafter/materials/aicodingsession/aicodingsession.go

@@ -252,16 +252,22 @@ type FileChange struct {
 
 // CodeChanges summarizes code modifications made during the session.
 type CodeChanges struct {
-	FilesModified     int          `json:"files_modified,omitempty"`
-	FilesCreated      int          `json:"files_created,omitempty"`
-	FilesDeleted      int          `json:"files_deleted,omitempty"`
-	LinesAdded        int          `json:"lines_added,omitempty"`
-	LinesRemoved      int          `json:"lines_removed,omitempty"`
-	AILinesAdded      int          `json:"ai_lines_added,omitempty"`
-	AILinesRemoved    int          `json:"ai_lines_removed,omitempty"`
-	HumanLinesAdded   int          `json:"human_lines_added,omitempty"`
-	HumanLinesRemoved int          `json:"human_lines_removed,omitempty"`
-	Files             []FileChange `json:"files,omitempty"`
+	FilesModified int `json:"files_modified,omitempty"`
+	FilesCreated  int `json:"files_created,omitempty"`
+	FilesDeleted  int `json:"files_deleted,omitempty"`
+	// Net lines of the session's commits (AI plus human); raw diff totals if a commit is unreadable.
+	LinesAdded   int `json:"lines_added,omitempty"`
+	LinesRemoved int `json:"lines_removed,omitempty"`
+	// Net committed lines attributed to the AI.
+	AILinesAdded   int `json:"ai_lines_added,omitempty"`
+	AILinesRemoved int `json:"ai_lines_removed,omitempty"`
+	// Net committed lines attributed to a human.
+	HumanLinesAdded   int `json:"human_lines_added,omitempty"`
+	HumanLinesRemoved int `json:"human_lines_removed,omitempty"`
+	// All lines of the session's agent edits, committed or not; not net.
+	AIGeneratedLinesAdded   int          `json:"ai_generated_lines_added,omitempty"`
+	AIGeneratedLinesRemoved int          `json:"ai_generated_lines_removed,omitempty"`
+	Files                   []FileChange `json:"files,omitempty"`
 }
 
 // Model holds information about the AI models used in the session.