grep expression

src/staxfile/expressions.ts

@@ -23,6 +23,7 @@ export default class Expressions {
     if (name === 'user_id') return process.getuid().toString()
     if (name === 'dasherize') return dasherize(args[0])
     if (name === 'exists') return existsSync(args[0]).toString()
+    if (name === 'grep') return this.grep(args[0], args[1]).toString()
 
     this.staxfile.warnings.add(`Invalid template expression: ${name}`)
   }
@@ -72,4 +73,10 @@ export default class Expressions {
       '${{ stax.ssh_auth_sock }}:${{ stax.ssh_auth_sock }}' :
       '${{ stax.host_services }}:/run/host-services'
   }
+
+  private grep(filename: string, pattern: string): boolean {
+    const content = this.read(filename, '')
+    const regex = new RegExp(pattern)
+    return regex.test(content)
+  }
 }

tests/unit/staxfile/expressions.test.js

@@ -1,4 +1,4 @@
-import { describe, it, expect, beforeEach } from 'bun:test'
+import { describe, it, expect, beforeEach, mock } from 'bun:test'
 import Expressions from '~/staxfile/expressions'
 import Staxfile from '~/staxfile'
 import os from 'os'
@@ -75,4 +75,41 @@ describe('Expressions', () => {
     console.log(staxfile.warnings)
     expect(staxfile.warnings).toContain("Undefined reference to 'stax.undefined_key'")
   })
+
+  describe('grep', () => {
+    let expressions
+    let mockStaxfile
+
+    beforeEach(() => {
+      mockStaxfile = {
+        warnings: { add: mock(() => {}) },
+        config: {
+          hasProperty: mock(() => true),
+          fetch: mock(() => 'mocked-value'),
+        },
+        location: {
+          readSync: mock(() => 'file content'),
+        },
+      }
+      expressions = new Expressions(mockStaxfile)
+    })
+
+    it('returns true when pattern is found in file', () => {
+      mockStaxfile.location.readSync.mockImplementation(() => 'Hello, world!')
+      const result = expressions.evaluate('grep', ['test.txt', 'world'])
+      expect(result).toBe('true')
+    })
+
+    it('returns false when pattern is not found in file', () => {
+      mockStaxfile.location.readSync.mockImplementation(() => 'Hello, world!')
+      const result = expressions.evaluate('grep', ['test.txt', 'foo'])
+      expect(result).toBe('false')
+    })
+
+    it('uses default value when file cannot be read', () => {
+      mockStaxfile.location.readSync.mockImplementation(() => { throw new Error('File not found') })
+      const result = expressions.evaluate('grep', ['nonexistent.txt', 'pattern'])
+      expect(result).toBe('false')
+    })
+  })
 })