fix(coverage): parse case subjects before in

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## Unreleased
 
 ### Fixed
-- Coverage propagates execution counts across multiline array literals, quoted strings, heredocs and backslash continuations, including when Bash 3.x records an array assignment on its closing `)`. Commands inside command and process substitutions remain individually tracked, even within quotes or arrays (#1338)
+- Coverage propagates execution counts across multiline array literals, quoted strings, heredocs and backslash continuations, including when Bash 3.x records an array assignment on its closing `)`. Parent statement hits no longer mark commands inside command or process substitutions as covered, including within quotes or arrays (#1338)
 
 ## [0.50.1](https://github.com/TypedDevs/bashunit/compare/0.50.0...0.50.1) - 2026-08-22
 

docs/coverage.md

@@ -429,8 +429,9 @@ These lines are not counted toward coverage:
 ### Statements That Span Several Lines
 
 Bash reports one executed statement to the tracer on a single line, even when
-the statement is written over several. bashunit spreads that hit across every
-line the statement occupies, so a statement that ran is covered on all of them:
+the statement is written over several. bashunit propagates that hit across the
+statement's physical span, so every executable line in a statement that ran is
+covered:
 
 - backslash continuations (`printf '%s' \` … )
 - array literals (`commands=(` … `)`)
@@ -444,11 +445,12 @@ commands=(          # covered
 )                   # not executable
 ```
 
-Every line still counts toward the denominator, so a multi-line statement that
-never runs reports as several uncovered lines, exactly as it did before.
+Executable lines remain in the denominator, so an unexecuted multiline
+statement can contribute several uncovered lines.
 
-Commands inside a multi-line command or process substitution are tracked
-individually, including substitutions inside a quoted string or array:
+Parent statement hits do not cover commands inside a multi-line command or
+process substitution, even when the substitution appears inside a quoted string
+or array:
 
 ```bash
 result=$(

src/coverage/lines.sh

@@ -235,8 +235,8 @@ function bashunit::coverage::_ends_with_continuation() {
 #   S  a single-quoted string      D  a double-quoted string
 #   A  an array literal `name=(`   C  a command/process substitution
 #   R  an arithmetic parenthesis  P  any other parenthesis
-#   H  a case command header       K  a case expecting a pattern
-#   B  a case arm body
+#   Q  a case awaiting its subject H  a case header after its subject
+#   K  a case expecting a pattern B  a case arm body
 #
 # plus a pending heredoc delimiter. A line is *open* -- the statement continues
 # onto the next line -- when the stack holds an S, D or A, when a heredoc is
@@ -394,6 +394,11 @@ function bashunit::coverage::scan_line() {
         words="${words#"$token"}"
         top="${stack#"${stack%?}"}"
         case "$top:$token" in
+        'Q:'*)
+          # A case subject may itself be the word `in`.
+          stack="${stack%?}H"
+          command_start=1
+          ;;
         'H:in')
           stack="${stack%?}K"
           command_start=1
@@ -411,7 +416,7 @@ function bashunit::coverage::scan_line() {
           command_start=0
           ;;
         *':case')
-          stack="${stack}H"
+          stack="${stack}Q"
           command_start=1
           ;;
         *':if' | *':while' | *':until' | *':then' | *':do' | *':else' | *':elif' | *':{' | *':!')
@@ -431,7 +436,10 @@ function bashunit::coverage::scan_line() {
     # Nothing but the closing quote is reported inside `'..'`.
     if [ "$top" = 'S' ]; then
       stack="${stack%?}"
-      [ "${stack#"${stack%?}"}" = 'H' ] && command_start=1
+      case "${stack#"${stack%?}"}" in
+      'Q') stack="${stack%?}H"; command_start=1 ;;
+      'H') command_start=1 ;;
+      esac
       prev="$char"
       continue
     fi
@@ -452,7 +460,10 @@ function bashunit::coverage::scan_line() {
       case "$char" in
       '"')
         stack="${stack%?}"
-        [ "${stack#"${stack%?}"}" = 'H' ] && command_start=1
+        case "${stack#"${stack%?}"}" in
+        'Q') stack="${stack%?}H"; command_start=1 ;;
+        'H') command_start=1 ;;
+        esac
         ;;
       '$')
         # `"$(cmd 'a"b')"`: a command substitution reopens an unquoted context,
@@ -482,11 +493,11 @@ function bashunit::coverage::scan_line() {
     case "$char" in
     "'")
       stack="${stack}S"
-      case "$top" in A | H) : ;; *) command_start=0 ;; esac
+      case "$top" in A | Q | H) : ;; *) command_start=0 ;; esac
       ;;
     '"')
       stack="${stack}D"
-      case "$top" in A | H) : ;; *) command_start=0 ;; esac
+      case "$top" in A | Q | H) : ;; *) command_start=0 ;; esac
       ;;
     '#')
       # `#` only opens a comment at the start of a word, so `${x#y}` and
@@ -528,11 +539,11 @@ function bashunit::coverage::scan_line() {
         command_start=1
       else
         stack="${stack%?}"
-        if [ "${stack#"${stack%?}"}" = 'H' ]; then
-          command_start=1
-        else
-          command_start=0
-        fi
+        case "${stack#"${stack%?}"}" in
+        'Q') stack="${stack%?}H"; command_start=1 ;;
+        'H') command_start=1 ;;
+        *) command_start=0 ;;
+        esac
       fi
       ;;
     ';')

src/coverage/rules_awk.sh

@@ -113,8 +113,9 @@ function bu_ends_with_continuation(line,   lead, i, n) {
 #
 # _bu_st[1.._bu_sp] is the context stack, innermost last: S single-quoted,
 # D double-quoted, A array literal, C command/process substitution,
-# R arithmetic paren, P other paren, H case command header,
-# K case expecting a pattern, B case arm body.
+# R arithmetic paren, P other paren, Q case awaiting its subject,
+# H case header after its subject, K case expecting a pattern,
+# B case arm body.
 # The quote character itself has to be built with sprintf: this program lives
 # in a shell single-quoted string and so cannot contain one.
 function bu_scan_reset() {
@@ -160,7 +161,10 @@ function bu_scan_words(text,   token, top) {
     sub(/[ \t].*$/, "", token)
     text = substr(text, length(token) + 1)
     top = (_bu_sp > 0) ? _bu_st[_bu_sp] : ""
-    if (top == "H" && token == "in") {
+    if (top == "Q") {
+      # A case subject may itself be the word `in`.
+      _bu_st[_bu_sp] = "H"; _bu_command_start = 1
+    } else if (top == "H" && token == "in") {
       _bu_st[_bu_sp] = "K"; _bu_command_start = 1
     } else if (top == "H") {
       # Subject words continue until the unquoted `in` keyword.
@@ -171,7 +175,7 @@ function bu_scan_words(text,   token, top) {
       # `case` here is a pattern word, not a nested command.
       _bu_command_start = 0
     } else if (token == "case") {
-      _bu_st[++_bu_sp] = "H"; _bu_command_start = 1
+      _bu_st[++_bu_sp] = "Q"; _bu_command_start = 1
     } else if (token == "if" || token == "while" || token == "until" ||
         token == "then" || token == "do" || token == "else" ||
         token == "elif" || token == "{" || token == "!") {
@@ -247,6 +251,7 @@ function bu_scan_line(line,   i, n, c, prev, top, body, rest, offset, lead, keyw
     if (top == "S") {
       if (c == _bu_sq) {
         _bu_sp--
+        if (_bu_sp > 0 && _bu_st[_bu_sp] == "Q") { _bu_st[_bu_sp] = "H" }
         if (_bu_sp > 0 && _bu_st[_bu_sp] == "H") { _bu_command_start = 1 }
       }
       prev = c
@@ -264,6 +269,7 @@ function bu_scan_line(line,   i, n, c, prev, top, body, rest, offset, lead, keyw
     if (top == "D") {
       if (c == "\"") {
         _bu_sp--
+        if (_bu_sp > 0 && _bu_st[_bu_sp] == "Q") { _bu_st[_bu_sp] = "H" }
         if (_bu_sp > 0 && _bu_st[_bu_sp] == "H") { _bu_command_start = 1 }
       }
       else if (c == "$" && substr(line, i + 1, 1) == "(") {
@@ -281,12 +287,12 @@ function bu_scan_line(line,   i, n, c, prev, top, body, rest, offset, lead, keyw
 
     if (c == _bu_sq) {
       _bu_sp++; _bu_st[_bu_sp] = "S"
-      if (top != "A" && top != "H") { _bu_command_start = 0 }
+      if (top != "A" && top != "Q" && top != "H") { _bu_command_start = 0 }
       prev = c; continue
     }
     if (c == "\"") {
       _bu_sp++; _bu_st[_bu_sp] = "D"
-      if (top != "A" && top != "H") { _bu_command_start = 0 }
+      if (top != "A" && top != "Q" && top != "H") { _bu_command_start = 0 }
       prev = c; continue
     }
     if (c == "#") {
@@ -322,6 +328,7 @@ function bu_scan_line(line,   i, n, c, prev, top, body, rest, offset, lead, keyw
       if (top == "K") { _bu_st[_bu_sp] = "B"; _bu_command_start = 1 }
       else {
         if (_bu_sp > 0) { _bu_sp-- }
+        if (_bu_sp > 0 && _bu_st[_bu_sp] == "Q") { _bu_st[_bu_sp] = "H" }
         _bu_command_start = (_bu_sp > 0 && _bu_st[_bu_sp] == "H")
       }
       prev = c

tests/unit/coverage/classifier_differential_test.sh

@@ -187,7 +187,7 @@ function test_the_rule_sets_agree_on_the_quirk_cases() {
       '      ;;' '  esac' ')"'
     printf '%s\n' 'result="$(' '  case x in' '    (x) case y in' '      y) : ;;' \
       '    esac ;;' '  esac' ')"'
-    printf '%s\n' 'result="$(' '  case z in (x) case y in' '    y) : ;;' \
+    printf '%s\n' 'result="$(' '  case in in (x) case y in' '    y) : ;;' \
       '  esac ;;' '  esac' ')"'
     printf '%s\n' 'result="$(' '  case z in' '    foo|esac)' '      : arm' \
       '      ;;' '  esac' ')"'

tests/unit/coverage/spans_test.sh

@@ -363,9 +363,9 @@ function test_optional_case_pattern_keeps_nested_case_commands_isolated() {
   assert_empty "$(awk_stack_for_file "$src")"
 }
 
-function test_compact_optional_case_pattern_keeps_nested_commands_isolated() {
+function test_case_subject_named_in_keeps_compact_nested_commands_isolated() {
   local src="$WORK/compact_optional_nested_case.sh"
-  printf '%s\n' 'result="$(' '  case z in (x) case y in' '    y) : ;;' \
+  printf '%s\n' 'result="$(' '  case in in (x) case y in' '    y) : ;;' \
     '  esac ;;' '  z)' '    if false; then' '      echo skipped' '    fi' \
     '    ;;' '  esac' ')"' >"$src"