fix(claude-action): account a cancelled session from its session JSONL

claude/action.yaml

@@ -108,7 +108,10 @@ outputs:
     description: >-
       JSON object with token usage: input_tokens, output_tokens,
       cache_creation_input_tokens, cache_read_input_tokens, turns,
-      model, cost_usd
+      model, cost_usd, partial. `partial` is true when the run emitted no
+      result event (typically a cancellation) and the counts were
+      reconstructed from the session log; `cost_usd` is null in that case,
+      since only the result event carries it.
     value: ${{ steps.tokens.outputs.usage }}
 
 runs:
@@ -527,14 +530,10 @@ runs:
           echo "" >> "$GITHUB_STEP_SUMMARY"
         fi
 
-    # Parse the stream-json the headless run wrote to stdout. It is NDJSON (one
-    # SDK message event per line) containing one or more `type: "result"`
-    # events. Sessions that use `run_in_background: true` Bash emit a second
-    # `result` on wakeup; `usage.*` and `num_turns` are per-event, while
-    # `total_cost_usd` is cumulative. Sum the per-event fields across all
-    # entries and take cost from the last. Output shape mirrors the interactive
-    # harness so downstream consumers (review-reviewers' evidence gist,
-    # token-report.sh, dashboards) don't branch on harness.
+    # Account the run's token usage from the stream-json the headless run wrote
+    # to stdout, falling back to the session JSONL when the run was cancelled
+    # before it emitted a `type: "result"` event. Both parsers live in
+    # compute-token-usage.sh so pytest can cover them.
     - name: Token usage
       if: always()
       id: tokens
@@ -555,29 +554,9 @@ runs:
         cp -a "${AGENT_HOME}/.claude/projects/." "$LOGS_DIR/" 2>/dev/null || true
         cp -a "$RUNNER_TEMP/tend-claude-stderr.log" "$LOGS_DIR/" 2>/dev/null || true
 
-        if [ -n "${STREAM_JSON:-}" ] && [ -s "$STREAM_JSON" ]; then
-          USAGE=$(jq -s -c --arg model "$MODEL" '
-            (map(select(.type == "result"))) as $rs |
-            if ($rs | length) == 0 then
-              {input_tokens:0, output_tokens:0, cache_creation_input_tokens:0,
-               cache_read_input_tokens:0, turns:0, model:$model, cost_usd:0}
-            else
-              ($rs | last) as $r |
-              {
-                input_tokens: ([$rs[].usage.input_tokens // 0] | add),
-                output_tokens: ([$rs[].usage.output_tokens // 0] | add),
-                cache_creation_input_tokens: ([$rs[].usage.cache_creation_input_tokens // 0] | add),
-                cache_read_input_tokens: ([$rs[].usage.cache_read_input_tokens // 0] | add),
-                turns: ([$rs[].num_turns // 0] | add),
-                model: $model,
-                cost_usd: (($r.total_cost_usd // 0) * 100 | round / 100)
-              }
-            end
-          ' "$STREAM_JSON" 2>/dev/null || echo '')
-        fi
-        if [ -z "${USAGE:-}" ]; then
-          USAGE='{"input_tokens":0,"output_tokens":0,"cache_creation_input_tokens":0,"cache_read_input_tokens":0,"turns":0,"model":"'"$MODEL"'","cost_usd":0}'
-        fi
+        # Runs after the copy above, so the fallback can read the session JSONL.
+        USAGE=$(LOGS_DIR="$LOGS_DIR" \
+          bash "${{ github.action_path }}/../shared/steps/compute-token-usage.sh")
 
         echo "$USAGE" > "$LOGS_DIR/token-usage.json"
         echo "usage=$(jq -c . <<< "$USAGE")" >> "$GITHUB_OUTPUT"
@@ -593,7 +572,7 @@ runs:
         fi
 
         jq -r '
-          def usd: tostring | if test("\\.") then split(".") | "\(.[0]).\((.[1] + "00")[:2])" else . + ".00" end | "$" + .;
+          def usd: if . == null then "unknown" else tostring | if test("\\.") then split(".") | "\(.[0]).\((.[1] + "00")[:2])" else . + ".00" end | "$" + . end;
           "## Token Usage",
           "| Metric | Value |",
           "|--------|-------|",
@@ -604,6 +583,9 @@ runs:
           "| Cost | \(.cost_usd | usd) |",
           "| Turns | \(.turns) |",
           "",
+          if .partial then
+            "*Reconstructed from the session log: this run emitted no result event (most often a cancellation), so the token counts are its own but the cost is not recoverable.*"
+          else empty end,
           "*Cost at API list prices — a large multiple of the effective rate on Claude Code subscriptions.*"
         ' <<< "$USAGE" >> "$GITHUB_STEP_SUMMARY"