feat(cli): variable expansion, scalar bool/int support, precedence fix

- Add $VAR / ${VAR} expansion in effective context (ctx.ExpandVars):
  iterates up to 10 passes to resolve transitive chains; circular
  references are left as-is after the limit.
- Handle non-string YAML scalars (bool, int, float64) in
  ExtractStringVars and varValueString via new ScalarString helper;
  values like BUILD: true no longer render as "(complex)" or get
  silently dropped from the effective context.
- Variable precedence (GitLab spec): pipeline defaults < workflow-rule
  vars < CLI --var flags; implemented correctly in enrichContext;
  expansion applied after all sources are merged.
- Update README, CHANGELOG, ROADMAP for v0.2.13.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,18 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 This project uses [Semantic Versioning](https://semver.org).
 
+## [0.2.13] - 2026-06-12
+
+### Added
+
+- **Variable expansion (`$VAR` / `${VAR}`)** — variable values that reference other variables are now expanded in the effective context after all sources are merged. Transitive chains (`A=$B`, `B=$C`) are resolved over up to ten passes; circular references are left as-is. The expanded values are visible in `--list-vars` output under "Effective context variables" and are used when evaluating `rules:if:` expressions.
+
+- **Non-string scalar variables (`bool`, `int`, `float64`)** — variables declared with bare `true`/`false` or integer values (e.g. `BUILD: true`, `RETRIES: 3`) are now handled correctly in all variable processing paths. Previously they were rendered as `(complex)` in `--list-vars` output and silently dropped from the effective context; they now render and inject as their string equivalents (`"true"`, `"3"`), matching GitLab CI's own behaviour where all variable values are strings.
+
+### Fixed
+
+- **YAML `\/` escape in double-quoted strings** — regex patterns containing `\/` (escaped forward-slash) in double-quoted `if:` expressions (e.g. `$CI_COMMIT_BRANCH =~ /^us\//`) caused a YAML parse error (`found unknown escape character`) with `gopkg.in/yaml.v3`, which does not implement this YAML 1.2 escape. The parser now preprocesses the raw bytes before unmarshalling: inside double-quoted strings, `\/` is rewritten to `\\/`, which `yaml.v3` parses as a literal backslash followed by a slash — preserving the regex intent.
+
 ## [0.2.11] - 2026-06-12
 
 ### Added

README.md

@@ -6,7 +6,7 @@
 
 <p align="center">
   <a href="LICENSE"><img src="https://img.shields.io/badge/license-Apache%202.0-blue.svg" alt="License"></a>
-  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.11-blue.svg" alt="Release"></a>
+  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.13-blue.svg" alt="Release"></a>
 </p>
 
 > **Disclaimer:** This tool was built through iterative AI-assisted development with [Claude](https://claude.ai). It is experimental, incomplete, and not intended for production use. Coverage of GitLab CI keywords is best-effort and may lag behind GitLab's evolving spec. Use it at your own discretion — no correctness guarantees are made. Contributions and bug reports are welcome.
@@ -28,6 +28,8 @@ A local tool to validate and lint `.gitlab-ci.yml` pipelines without needing a G
 - **Extended variable declarations** — `variables:` entries may use the `{value, description, options}` map form (GitLab CI 13.7+); `default.image` accepts both string and map form; `rules.changes`/`rules.exists` accept both list and `{paths, compare_to}` map form
 - **Graph output** — `glint graph` prints a job tree (stages → jobs) to the terminal; `glint graph includes` emits a Mermaid include dependency diagram; `glint graph pipeline` renders a GitLab CI-style PNG/SVG
 - **Context simulation** — pass `--branch`, `--tag`, or `--source` to `glint check` or `glint graph` to see which jobs would be active, manual, or skipped for a specific pipeline event; evaluates `rules:if:` expressions and `only`/`except` filters
+- **Variable expansion** — `$VAR` and `${VAR}` references inside variable values are expanded after all sources are merged (pipeline defaults → workflow-rule overrides → CLI flags); transitive chains resolve automatically; visible via `--list-vars`
+- **Non-string variable scalars** — `BUILD: true`, `RETRIES: 3` and other bare boolean/integer variable values are handled correctly throughout: they render in `--list-vars` output and are injected into the evaluation context as their string equivalents, matching GitLab CI's behaviour
 
 See [ROADMAP.md](ROADMAP.md) for planned improvements.
 
@@ -200,6 +202,7 @@ glint check --branch main --var DEPLOY_ENV=production .gitlab-ci.yml
 **Evaluated:**
 - `rules:if:` — full expression language: `==`, `!=`, `=~`, `!~`, `&&`, `||`, `!`, `()`, `$VAR`, string literals, `null`
 - `only:` / `except:` — ref keywords (`branches`, `tags`, `merge_requests`, `schedules`, …), branch name globs (`feat/*`), and `/regex/` patterns
+- Variable expansion — `$VAR` / `${VAR}` references within variable values are expanded after all sources are merged; use `--list-vars` to inspect the resolved values
 
 **Not evaluated** (no git tree at lint time): `rules:changes:`, `rules:exists:`.
 Rules without an `if:` clause always match.

ROADMAP.md

@@ -4,7 +4,7 @@ This document tracks planned improvements to `glint`. Items are grouped by theme
 
 ---
 
-## Context-aware validation — ✓ single-context shipped in v0.2.0; expression evaluator hardened post-v0.2.0; implicit defaults and --list-vars shipped v0.2.11
+## Context-aware validation — ✓ single-context shipped in v0.2.0; expression evaluator hardened post-v0.2.0; implicit defaults and --list-vars shipped v0.2.11; variable expansion and scalar handling shipped v0.2.13
 
 Single-context simulation is fully implemented. Pass `--branch`, `--tag`, `--source`, or `--var` to either `glint check` or `glint graph`; jobs are evaluated and shown as active / manual / skipped.
 
@@ -30,6 +30,12 @@ glint graph tree --branch main .gitlab-ci.yml   # tree annotated with [skipped]
 
 ~~**`--list-vars` debug flag**~~ — ✓ shipped v0.2.11; prints sorted `KEY=VALUE` of all collected variables (pipeline YAML + included files + workflow-rule union + effective context) to stderr.
 
+**Shipped in v0.2.13**
+
+- ✓ **Variable expansion** — `$VAR` / `${VAR}` references within variable values are expanded after all sources are merged; transitive chains resolve over multiple passes; visible in `--list-vars` effective-context output.
+- ✓ **Non-string scalar variables** — `BUILD: true`, `RETRIES: 3` and similar bare boolean/integer values now render correctly in `--list-vars` and are injected into the evaluation context as string equivalents; previously shown as `(complex)` and silently dropped.
+- ✓ **YAML `\/` escape in double-quoted strings** — regex patterns like `/^us\//` in double-quoted `if:` blocks no longer cause a parse error; the raw bytes are preprocessed before YAML unmarshalling.
+
 **Remaining work**
 
 - **Multi-context simulation** — run multiple contexts in one invocation and print a comparison table:
@@ -52,7 +58,7 @@ The current rule set covers the most common sources of broken pipelines. These a
 - **`id_tokens:` / `secrets:`** — presence and required-key checks
 - **`pages:publish`** — validate that the path is consistent with `artifacts.paths`
 - **`inherit:` completeness** — flag when a job overrides a default field that would require `inherit: default: false` to suppress
-- **Unreachable jobs** — detect jobs that can never run because every `rules:` branch evaluates to `never` (static analysis only, no variable expansion)
+- **Unreachable jobs** — detect jobs that can never run because every `rules:` branch evaluates to `never` (static analysis only)
 - **Duplicate stage names** — GitLab silently merges them; warn to avoid confusion
 - **`cache:key:files`** — must be a list of paths, not a glob
 

cmd/glint/main.go

@@ -404,14 +404,8 @@ func printVarMap(m map[string]any) {
 }
 
 func varValueString(v any) string {
-	switch val := v.(type) {
-	case string:
-		return val
-	case map[string]any:
-		if s, ok := val["value"].(string); ok {
-			return s
-		}
-		return "(complex)"
+	if s, ok := cicontext.ScalarString(v); ok {
+		return s
 	}
 	return "(complex)"
 }
@@ -432,6 +426,9 @@ func enrichContext(ctx *cicontext.Context, p *model.Pipeline) {
 	for k, v := range ruleVars {
 		ctx.Inject(k, v)
 	}
+	// Expand $VAR / ${VAR} references within variable values now that all
+	// sources (pipeline, workflow rules, CLI) have been merged.
+	ctx.ExpandVars()
 }
 
 func printContext(p *model.Pipeline, ctx *cicontext.Context) {

internal/cicontext/context.go

@@ -1,6 +1,9 @@
 package cicontext
 
-import "strings"
+import (
+	"fmt"
+	"strings"
+)
 
 // Context holds the simulated CI execution environment used for context-aware
 // pipeline evaluation (rules:if:, only:, except:, workflow:rules:).
@@ -117,26 +120,131 @@ func (c *Context) Summary() string {
 
 // ExtractStringVars converts a map[string]any variable block (as used by
 // Pipeline.Variables and Rule.Variables) to a flat map[string]string.
-// Plain string values are used directly. Extended {value: "..."} map form
-// uses the "value" key. Other forms are skipped.
+// Plain string values are used directly. Extended {value: ...} map form uses
+// the "value" key. Scalar non-string values (bool, int, float64) are
+// converted to their string representation, matching GitLab's own behaviour
+// where all CI variable values are strings.
 func ExtractStringVars(m map[string]any) map[string]string {
 	if len(m) == 0 {
 		return nil
 	}
 	out := make(map[string]string, len(m))
 	for k, v := range m {
-		switch val := v.(type) {
-		case string:
-			out[k] = val
-		case map[string]any:
-			if s, ok := val["value"].(string); ok {
-				out[k] = s
-			}
+		if s, ok := ScalarString(v); ok {
+			out[k] = s
 		}
 	}
 	return out
 }
 
+// ScalarString converts a YAML-decoded CI variable value to its string
+// representation. Handles plain scalars and the extended {value: ...} map
+// form. Returns (s, true) on success, ("", false) for unrecognised forms.
+func ScalarString(v any) (string, bool) {
+	switch val := v.(type) {
+	case string:
+		return val, true
+	case bool:
+		return fmt.Sprintf("%t", val), true
+	case int:
+		return fmt.Sprintf("%d", val), true
+	case float64:
+		return fmt.Sprintf("%g", val), true
+	case map[string]any:
+		inner, ok := val["value"]
+		if !ok {
+			return "", false
+		}
+		return ScalarString(inner)
+	}
+	return "", false
+}
+
+// ExpandVars expands $VAR and ${VAR} references within every value in
+// ctx.Vars, using the same map as the expansion source. Iteration repeats
+// (up to 10 passes) so transitive chains like A=$B, B=$C resolve fully.
+// Variables that form circular references are left as-is after the limit.
+func (c *Context) ExpandVars() {
+	if c == nil || len(c.Vars) == 0 {
+		return
+	}
+	for range 10 {
+		changed := false
+		for k, v := range c.Vars {
+			expanded := expandVarRefs(v, c.Vars)
+			if expanded != v {
+				c.Vars[k] = expanded
+				changed = true
+			}
+		}
+		if !changed {
+			return
+		}
+	}
+}
+
+// expandVarRefs replaces $VAR and ${VAR} occurrences in s with their values
+// from vars. Unknown variables are left unchanged.
+func expandVarRefs(s string, vars map[string]string) string {
+	if !strings.Contains(s, "$") {
+		return s
+	}
+	var sb strings.Builder
+	i := 0
+	for i < len(s) {
+		if s[i] != '$' {
+			sb.WriteByte(s[i])
+			i++
+			continue
+		}
+		i++ // consume '$'
+		if i >= len(s) {
+			sb.WriteByte('$')
+			break
+		}
+		if s[i] == '{' {
+			i++ // consume '{'
+			j := i
+			for j < len(s) && isIdentByte(s[j]) {
+				j++
+			}
+			if j < len(s) && s[j] == '}' {
+				name := s[i:j]
+				if val, ok := vars[name]; ok {
+					sb.WriteString(val)
+				} else {
+					sb.WriteString("${")
+					sb.WriteString(name)
+					sb.WriteByte('}')
+				}
+				i = j + 1
+			} else {
+				// Malformed ${…} — emit literally
+				sb.WriteString("${")
+				i = j
+			}
+		} else {
+			j := i
+			for j < len(s) && isIdentByte(s[j]) {
+				j++
+			}
+			if j > i {
+				name := s[i:j]
+				if val, ok := vars[name]; ok {
+					sb.WriteString(val)
+				} else {
+					sb.WriteByte('$')
+					sb.WriteString(name)
+				}
+				i = j
+			} else {
+				sb.WriteByte('$')
+			}
+		}
+	}
+	return sb.String()
+}
+
 // slugify converts a ref name to its GitLab slug form:
 // lowercased, non-alphanumeric characters replaced with '-', leading/trailing '-' removed.
 func slugify(s string) string {