Boilerplate unit tests for expressionParserUtil

tests-ui/tests/utils/expressionParserUtil.test.ts

@@ -0,0 +1,120 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+  ContextValue,
+  evaluateExpression,
+  parseAST,
+  tokenize
+} from '@/utils/expressionParserUtil'
+
+describe('tokenize()', () => {
+  it('splits identifiers, literals, operators and parentheses', () => {
+    const tokens = tokenize('a && !b || (c == "d")')
+    expect(tokens.map((t) => t.t)).toEqual([
+      'a',
+      '&&',
+      '!',
+      'b',
+      '||',
+      '(',
+      'c',
+      '==',
+      '"d"',
+      ')'
+    ])
+  })
+
+  it('throws on encountering invalid characters', () => {
+    expect(() => tokenize('a & b')).toThrowError(/Invalid character/)
+  })
+})
+
+describe('parseAST()', () => {
+  it('parses a single identifier', () => {
+    const ast = parseAST(tokenize('x'))
+    expect(ast).toEqual({ type: 'Identifier', name: 'x' })
+  })
+
+  it('respects default precedence (&& over ||)', () => {
+    const ast = parseAST(tokenize('a || b && c'))
+    expect(ast).toEqual({
+      type: 'Binary',
+      op: '||',
+      left: { type: 'Identifier', name: 'a' },
+      right: {
+        type: 'Binary',
+        op: '&&',
+        left: { type: 'Identifier', name: 'b' },
+        right: { type: 'Identifier', name: 'c' }
+      }
+    })
+  })
+
+  it('honors parentheses to override precedence', () => {
+    const ast = parseAST(tokenize('(a || b) && c'))
+    expect(ast).toEqual({
+      type: 'Binary',
+      op: '&&',
+      left: {
+        type: 'Binary',
+        op: '||',
+        left: { type: 'Identifier', name: 'a' },
+        right: { type: 'Identifier', name: 'b' }
+      },
+      right: { type: 'Identifier', name: 'c' }
+    })
+  })
+
+  it('parses unary NOT correctly', () => {
+    const ast = parseAST(tokenize('!a && b'))
+    expect(ast).toEqual({
+      type: 'Binary',
+      op: '&&',
+      left: { type: 'Unary', op: '!', arg: { type: 'Identifier', name: 'a' } },
+      right: { type: 'Identifier', name: 'b' }
+    })
+  })
+})
+
+describe('evaluateExpression()', () => {
+  const context: Record<string, ContextValue> = {
+    a: true,
+    b: false,
+    c: true,
+    d: '',
+    num1: 1,
+    num0: 0
+  }
+  const getContextKey = (key: string) => context[key]
+
+  it('returns true for empty expression', () => {
+    expect(evaluateExpression('', getContextKey)).toBe(true)
+  })
+
+  it('evaluates literals and basic comparisons', () => {
+    expect(evaluateExpression('"hi"', getContextKey)).toBe(true)
+    expect(evaluateExpression("''", getContextKey)).toBe(false)
+    expect(evaluateExpression('1', getContextKey)).toBe(true)
+    expect(evaluateExpression('0', getContextKey)).toBe(false)
+    expect(evaluateExpression('1 == 1', getContextKey)).toBe(true)
+    expect(evaluateExpression('1 != 2', getContextKey)).toBe(true)
+    expect(evaluateExpression("'x' == 'y'", getContextKey)).toBe(false)
+  })
+
+  it('evaluates logical AND, OR and NOT', () => {
+    expect(evaluateExpression('a && b', getContextKey)).toBe(false)
+    expect(evaluateExpression('a || b', getContextKey)).toBe(true)
+    expect(evaluateExpression('!b', getContextKey)).toBe(true)
+  })
+
+  it('respects operator precedence and parentheses', () => {
+    expect(evaluateExpression('a || b && c', getContextKey)).toBe(true)
+    expect(evaluateExpression('(a || b) && c', getContextKey)).toBe(true)
+    expect(evaluateExpression('!(a && b) || c', getContextKey)).toBe(true)
+  })
+
+  it('safely handles syntax errors by returning false', () => {
+    expect(evaluateExpression('a &&', getContextKey)).toBe(false)
+    expect(evaluateExpression('foo $ bar', getContextKey)).toBe(false)
+  })
+})