Refactor occurrence finder algorithm to fix edge cases

.github/actions/coverage/action.yml

@@ -0,0 +1,10 @@
+name: Test Coverage
+description: Send coverage to Coveralls
+
+runs:
+  using: "composite"
+  steps:
+    - name: Send coverage
+      uses: shogo82148/actions-goveralls@v1
+      with:
+        path-to-profile: cover.out

.github/actions/go-setup/action.yml

@@ -0,0 +1,15 @@
+name: Go Setup
+description: Setup Go and install dependencies
+
+runs:
+  using: "composite"
+  steps:
+    - uses: actions/setup-go@v6
+      with:
+        go-version: "1.25.7"
+
+    - name: Setup dependencies
+      shell: bash
+      run: |
+        go install github.com/magefile/mage
+        mage -v bootstrap

.github/actions/test/action.yml

@@ -0,0 +1,15 @@
+name: Test
+description: Run Go tests
+
+runs:
+  using: "composite"
+  steps:
+    - name: Run Tests
+      shell: bash
+      run: mage -v test
+
+    - name: Run Build
+      shell: bash
+      run: |
+        mage -v build:release
+        ls -la bin

.github/workflows/test-dev.yml

@@ -0,0 +1,21 @@
+name: Test Dev
+
+on:
+  push:
+    branches: [dev]
+  pull_request:
+    branches: [dev]
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    name: Run Tests
+
+    steps:
+      - uses: actions/checkout@v6
+      - name: Go Setup
+        uses: ./.github/actions/go-setup
+
+      - name: Run Tests
+        uses: ./.github/actions/test

.github/workflows/test-master.yml

@@ -0,0 +1,24 @@
+name: Test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  workflow_dispatch:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    name: Run Tests
+
+    steps:
+      - uses: actions/checkout@v6
+      - name: Go Setup
+        uses: ./.github/actions/go-setup
+
+      - name: Run Tests
+        uses: ./.github/actions/test
+
+      - name: Send coverage
+        uses: ./.github/actions/coverage

command/run.go

@@ -22,7 +22,7 @@ func (c *RunCommand) Help() string {
 	jsInfo := c.UI.Colorize(".js", c.UI.InfoColor)
 	helpText := fmt.Sprintf(`
 Usage: reactenv run [options] PATH
-  
+
 Inject environment variables into a built react app.
 
 Example:
@@ -84,7 +84,13 @@ func (c *RunCommand) Run(args []string) int {
 		os.Exit(1)
 	}
 
-	renv.FindOccurrences()
+	err = renv.FindOccurrences()
+
+	if err != nil {
+		c.UI.Error(fmt.Sprintf("There was an error while searching for __reactenv variables in the %d '%s' files within '%s', therefore nothing was injected.\n", renv.FilesMatchTotal, fileMatchExpression, pathToAssets))
+		c.UI.Error(fmt.Sprintf("%v", err))
+		os.Exit(1)
+	}
 
 	if renv.OccurrencesTotal == 0 {
 		c.UI.Warn(ui.WrapAtLength(fmt.Sprintf("No reactenv environment variables were found in any of the %d '%s' files within '%s', therefore nothing was injected.\n", renv.FilesMatchTotal, fileMatchExpression, pathToAssets), 0))

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/mitchellh/gox v1.0.1
 	github.com/posener/complete v1.2.3
 	github.com/schollz/progressbar/v3 v3.19.0
+	github.com/stretchr/testify v1.11.1
 	gotest.tools/gotestsum v1.13.0
 )
 
@@ -22,6 +23,7 @@ require (
 	github.com/armon/go-radix v1.0.0 // indirect
 	github.com/bgentry/speakeasy v0.2.0 // indirect
 	github.com/bitfield/gotestdox v0.2.2 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dnephin/pflag v1.0.7 // indirect
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
@@ -36,6 +38,7 @@ require (
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/iochan v1.0.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/shopspring/decimal v1.4.0 // indirect
 	github.com/spf13/cast v1.10.0 // indirect
@@ -46,4 +49,5 @@ require (
 	golang.org/x/term v0.40.0 // indirect
 	golang.org/x/text v0.34.0 // indirect
 	golang.org/x/tools v0.42.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -106,8 +106,8 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
-github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200414173820-0848c9571904/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
@@ -130,6 +130,7 @@ golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
 golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
 golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

magefile.go

@@ -51,15 +51,23 @@ func Test() error {
 	log := NewLogger()
 	defer log.End()
 	return RunSync([][]string{
-		{"gotestsum", "--format", "pkgname", "--", "--cover", "./..."},
+		{"gotestsum", "--format", "pkgname", "--", "-coverprofile", "cover.out", "./..."},
+	})
+}
+
+func TestWatch() error {
+	log := NewLogger()
+	defer log.End()
+	return RunSync([][]string{
+		{"gotestsum", "--watch", "--format", "pkgname", "--", "./..."},
 	})
 }
 
 func Bench() error {
 	log := NewLogger()
 	defer log.End()
 	return RunSync([][]string{
-		{"gotestsum", "--format", "pkgname", "--", "--cover", "-bench", ".", "-benchmem", "./..."},
+		{"gotestsum", "--format", "pkgname", "--", "-bench", ".", "-benchmem", "./..."},
 	})
 }
 

npm/reactenv-darwin-arm64/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli-darwin-arm64",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "The macOS ARM 64-bit binary for reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "os": [

npm/reactenv-darwin-x64/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli-darwin-x64",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "The macOS 64-bit binary for reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "os": [

npm/reactenv-linux-arm64/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli-linux-arm64",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "The Linux ARM 64-bit binary for reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "os": [

npm/reactenv-linux-x64/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli-linux-x64",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "The Linux 64-bit binary for reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "os": [

npm/reactenv-win32-x64/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli-win32-x64",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "The Windows 64-bit binary for reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "os": [

npm/reactenv/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@reactenv/cli",
-    "version": "0.1.81",
+    "version": "0.1.88",
     "description": "reactenv, an experimental solution to inject env variables after a build.",
     "license": "Apache-2.0",
     "bin": {

reactenv/reactenv.go

@@ -1,6 +1,7 @@
 package reactenv
 
 import (
+	"bytes"
 	"fmt"
 	"io/fs"
 	"os"
@@ -12,8 +13,7 @@ import (
 )
 
 const (
-	REACTENV_PREFIX          = "__reactenv"
-	REACTENV_FIND_EXPRESSION = `(__reactenv\.[a-zA-Z_$][0-9a-zA-Z_$]*)`
+	REACTENV_PREFIX = "__reactenv"
 )
 
 type Reactenv struct {
@@ -22,7 +22,7 @@ type Reactenv struct {
 	// Path of directory to scan
 	Dir string
 
-	// Total file count (that match `REACTENV_FIND_EXPRESSION`, within `Dir`)
+	// Total file count - that have matches - within specified `Dir`
 	FilesMatchTotal int
 	// Files with occurrences (not every matched file will have an occurrence, so this may be less than `FilesMatchTotal`)
 	Files []*fs.DirEntry
@@ -62,6 +62,7 @@ func NewReactenv(ui *ui.Ui) *Reactenv {
 // Populates `Reactenv.Files` with all files that match `fileMatchExpression`
 func (r *Reactenv) FindFiles(dir string, fileMatchExpression string) error {
 	r.Dir = dir
+	r.Files = make([]*fs.DirEntry, 0)
 	files, err := os.ReadDir(r.Dir)
 
 	if err != nil {
@@ -76,7 +77,8 @@ func (r *Reactenv) FindFiles(dir string, fileMatchExpression string) error {
 
 	for _, file := range files {
 		if fileMatcher.MatchString(file.Name()) && !file.IsDir() {
-			r.Files = append(r.Files, &file)
+			fileEntry := file
+			r.Files = append(r.Files, &fileEntry)
 		}
 	}
 
@@ -120,8 +122,80 @@ func (r *Reactenv) FilesWalkContents(fileCb func(fileIndex int, file fs.DirEntry
 	return nil
 }
 
+// Strictly locates all instances of valid reactenv variables and returns their byte
+// start and end indices.
+//
+// This implementation allows for side-by-side occurrences, which a regex pattern
+// match would not (without an unsupported lookahead assertion).
+func FindAllOccurrenceBytePositions(data []byte, prefix []byte) [][]int {
+	// Guard against infinite loop allocation caused by empty prefixes.
+	if len(prefix) == 0 {
+		return nil
+	}
+
+	var indices [][]int
+
+	// Establish absolute boundaries by finding all prefix locations
+	var prefixStarts []int
+	offset := 0
+	for {
+		idx := bytes.Index(data[offset:], prefix)
+		if idx == -1 {
+			break
+		}
+		absoluteIdx := offset + idx
+		prefixStarts = append(prefixStarts, absoluteIdx)
+		offset = absoluteIdx + len(prefix)
+	}
+
+	// Iterate through boundaries and enforce positional grammar
+	for i, start := range prefixStarts {
+		current := start + len(prefix)
+
+		limit := len(data)
+		if i+1 < len(prefixStarts) {
+			limit = prefixStarts[i+1]
+		}
+
+		// Validate the initial character (cannot be a numeral).
+		if current < limit {
+			firstByte := data[current]
+			isValidStart := (firstByte >= 'a' && firstByte <= 'z') ||
+				(firstByte >= 'A' && firstByte <= 'Z') ||
+				firstByte == '_' || firstByte == '$'
+
+			if !isValidStart {
+				// Abort: The character following the dot is invalid
+				continue
+			}
+			current++
+		} else {
+			// Abort: The string terminates immediately after the dot
+			continue
+		}
+
+		// Scan forward for all subsequent valid identifier bytes
+		for current < limit {
+			b := data[current]
+			isValid := (b >= 'a' && b <= 'z') ||
+				(b >= 'A' && b <= 'Z') ||
+				(b >= '0' && b <= '9') ||
+				b == '_' || b == '$'
+
+			if !isValid {
+				break
+			}
+			current++
+		}
+
+		indices = append(indices, []int{start, current})
+	}
+
+	return indices
+}
+
 // Walks every file and populates `Reactenv.Occurrences*` fields.
-func (r *Reactenv) FindOccurrences() {
+func (r *Reactenv) FindOccurrences() error {
 	// Reset occurrence fields
 	r.OccurrencesTotal = 0
 	r.OccurrencesByFile = make([]*FileOccurrences, 0)
@@ -133,8 +207,9 @@ func (r *Reactenv) FindOccurrences() {
 	newOccurrencesByFile := make([]*FileOccurrences, 0)
 	fileIndexesToRemove := make(map[int]int, 0)
 
-	r.FilesWalkContents(func(fileIndex int, file fs.DirEntry, filePath string, fileContents []byte) error {
-		fileOccurrences := regexp.MustCompile(REACTENV_FIND_EXPRESSION).FindAllIndex(fileContents, -1)
+	err := r.FilesWalkContents(func(fileIndex int, file fs.DirEntry, filePath string, fileContents []byte) error {
+		prefix := fmt.Appendf([]byte(""), "%s.", REACTENV_PREFIX)
+		fileOccurrences := FindAllOccurrenceBytePositions(fileContents, prefix)
 
 		fileOccurrencesToStore := make([]Occurrence, 0, len(fileOccurrences))
 		r.OccurrencesTotal += len(fileOccurrences)
@@ -166,6 +241,10 @@ func (r *Reactenv) FindOccurrences() {
 		return nil
 	})
 
+	if err != nil {
+		return err
+	}
+
 	// Remove files with no occurrences
 	if len(fileIndexesToRemove) > 0 {
 		for fileIndex, file := range r.Files {
@@ -178,6 +257,8 @@ func (r *Reactenv) FindOccurrences() {
 		r.Files = newFiles
 		r.OccurrencesByFile = newOccurrencesByFile
 	}
+
+	return nil
 }
 
 func (r *Reactenv) ReplaceOccurrences() {