update conditional variables

conditional-variables/action.yaml

@@ -1,45 +1,72 @@
+
 name: Conditional Variables
 
 description: |
-  Evaluates a list of conditions and exposes variables as outputs.
+  Evaluates a set of rules and exposes variables as outputs.
-  Conditions are evaluated in order. All matching conditions are applied.
+
-  If multiple conditions set the same variable, the last matching value wins.
+  Rules are evaluated in the order they are defined.
+
+  A rule matches when any of its conditions match the supplied context.
+
+  If multiple matching rules set the same variable,
+  the last matching value wins.
 
 inputs:
   context:
     description: |
-      Context variables available during condition evaluation.
+      Context variables available during rule evaluation.
-
-  conditions:
-    description: |
-      List of conditions to evaluate.
 
       Example:
 
-        - when:
+        branch=9.0-alpine-24
-            branch:
+        event=push
-              - 9.0-alpine-24
+        install_something=1
-              - 9.0-alpine-23
+
+    required: true
+
+  rules:
+    description: |
+      Rules to evaluate.
+
+      Example:
+
+        - conditions:
+            - branch == 9.0-alpine-24
+            - branch == 9.0-alpine-23
           set:
-            DOTNET_VERSION: 9.0
+            DOTNET_VERSION=9.0
+            DOTNET_RUNTIME_VERSION=9.0.18
+
+        - conditions:
+            - install_something == 1
+          set:
+            INSTALL_DEPENDENCY=true
+
+      Conditions within a rule are evaluated as OR.
 
     required: true
 
   fail-on-no-match:
     description: |
-      Fail the action when no condition matches.
+      Fail the action if no rule matches.
     required: false
     default: "false"
 
+outputs:
+  matched:
+    description: Indicates whether at least one rule matched.
+    value: ${{ steps.evaluate.outputs.matched }}
+
 runs:
   using: composite
 
   steps:
-    - name: Evaluate conditions
+    - name: Evaluate rules
+      id: evaluate
       shell: bash
       env:
         CONTEXT: ${{ inputs.context }}
-        CONDITIONS: ${{ inputs.conditions }}
+        RULES: ${{ inputs.rules }}
         FAIL_ON_NO_MATCH: ${{ inputs.fail-on-no-match }}
       run: |
         "${{ github.action_path }}/evaluate.sh"

conditional-variables/evaluate.sh

@@ -1,3 +1,8 @@
+declare -A context
+
+#
+# Remove leading/trailing whitespace
+#
 trim() {
     local var="$*"
     var="${var#"${var%%[![:space:]]*}"}"
@@ -5,48 +10,51 @@ trim() {
     printf '%s' "$var"
 }
 
-declare -A context
+#
+# Load key=value pairs into context array
+#
+load_context() {
+
+    while IFS='=' read -r key value; do
+
+        key="$(trim "${key:-}")"
+        value="$(trim "${value:-}")"
+
+        [[ -z "$key" ]] && continue
+        [[ "$key" =~ ^# ]] && continue
+
+        context["$key"]="$value"
+
+    done <<< "$CONTEXT"
+}
 
 #
-# Load context
+# Evaluate a single condition
 #
-while IFS='=' read -r key value; do
+# Examples:
-
+#   branch == 9.0
-    key="$(trim "${key:-}")"
+#   event != push
-    value="$(trim "${value:-}")"
+#   count > 10
-
-    [[ -z "$key" ]] && continue
-    [[ "$key" =~ ^# ]] && continue
-
-    context["$key"]="$value"
-
-done <<< "$CONTEXT"
-
-matched=false
-
 #
-# Evaluate conditions (OR)
+evaluate_condition() {
-#
-while IFS= read -r condition; do
 
-    condition="$(trim "${condition:-}")"
+    local condition="$1"
 
-    [[ -z "$condition" ]] && continue
+    local variable
-    [[ "$condition" =~ ^# ]] && continue
+    local operator
+    local expected
+    local actual
 
     read -r variable operator expected <<< "$condition"
 
-    #
-    # Validate condition format
-    #
     if [[ -z "${variable:-}" || -z "${operator:-}" || -z "${expected:-}" ]]; then
         echo "Invalid condition: $condition"
-        exit 1
+        return 1
     fi
 
     if [[ ! -v context["$variable"] ]]; then
         echo "Unknown context variable '$variable'"
-        exit 1
+        return 1
     fi
 
     actual="${context[$variable]}"
@@ -54,63 +62,78 @@ while IFS= read -r condition; do
     case "$operator" in
 
         "==")
-            [[ "$actual" == "$expected" ]] && matched=true
+            [[ "$actual" == "$expected" ]]
             ;;
 
         "!=")
-            [[ "$actual" != "$expected" ]] && matched=true
+            [[ "$actual" != "$expected" ]]
             ;;
 
         ">"|">="|"<"|"<=")
 
-            #
-            # Numeric comparisons only
-            #
             if [[ ! "$actual" =~ ^-?[0-9]+$ ]]; then
                 echo "Numeric operator '$operator' requires integer value. Actual: '$actual'"
-                exit 1
+                return 1
             fi
 
             if [[ ! "$expected" =~ ^-?[0-9]+$ ]]; then
-                echo "Numeric operator '$operator' requires integer comparison value. Expected: '$expected'"
+                echo "Numeric operator '$operator' requires integer value. Expected: '$expected'"
-                exit 1
+                return 1
             fi
 
             case "$operator" in
                 ">")
-                    (( actual > expected )) && matched=true
+                    (( actual > expected ))
                     ;;
                 ">=")
-                    (( actual >= expected )) && matched=true
+                    (( actual >= expected ))
                     ;;
                 "<")
-                    (( actual < expected )) && matched=true
+                    (( actual < expected ))
                     ;;
                 "<=")
-                    (( actual <= expected )) && matched=true
+                    (( actual <= expected ))
                     ;;
             esac
             ;;
 
         *)
             echo "Unsupported operator: $operator"
-            exit 1
+            return 1
             ;;
-
     esac
-
+}
-    #
-    # OR logic:
-    # stop at first match
-    #
-    [[ "$matched" == true ]] && break
-
-done <<< "$CONDITIONS"
 
 #
-# Set outputs
+# Evaluate list of conditions
 #
-if [[ "$matched" == true ]]; then
+# Conditions are OR'd together
+#
+evaluate_conditions() {
+
+    local matched=false
+
+    while IFS= read -r condition; do
+
+        condition="$(trim "${condition:-}")"
+
+        [[ -z "$condition" ]] && continue
+        [[ "$condition" =~ ^# ]] && continue
+
+        if evaluate_condition "$condition"; then
+            matched=true
+            break
+        fi
+
+    done <<< "$CONDITIONS"
+
+    [[ "$matched" == true ]]
+}
+
+#
+# Write outputs
+#
+apply_variables() {
 
     while IFS= read -r output; do
 
@@ -119,23 +142,36 @@ if [[ "$matched" == true ]]; then
         [[ -z "$output" ]] && continue
         [[ "$output" =~ ^# ]] && continue
 
-        #
-        # Validate output syntax
-        #
         if [[ ! "$output" =~ ^[A-Za-z_][A-Za-z0-9_]*= ]]; then
             echo "Invalid variable definition: $output"
-            exit 1
+            return 1
         fi
 
         echo "$output" >> "$GITHUB_OUTPUT"
 
     done <<< "$VARIABLES"
+}
 
-fi
+#
+# Main
+#
+main() {
 
-if [[ "$matched" == false && "$FAIL_ON_NO_MATCH" == "true" ]]; then
+    load_context
-    echo "No conditions matched"
-    exit 1
-fi
 
-echo "matched=$matched" >> "$GITHUB_OUTPUT"
+    local matched=false
+
+    if evaluate_conditions; then
+        matched=true
+        apply_variables
+    fi
+
+    if [[ "$matched" == false && "$FAIL_ON_NO_MATCH" == "true" ]]; then
+        echo "No conditions matched"
+        exit 1
+    fi
+
+    echo "matched=$matched" >> "$GITHUB_OUTPUT"
+}
+
+main