{"id":"920a667dfc09a287","repo":"evanw/esbuild","slug":"invalid-package-name-in-alias-old","errorCode":null,"errorMessage":"Invalid package name in alias: ${old}","messagePattern":"Invalid package name in alias: (.+?)","errorType":"validation","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"lib/shared/common.ts","lineNumber":314,"sourceCode":"  if (splitting) flags.push('--splitting')\n  if (preserveSymlinks) flags.push('--preserve-symlinks')\n  if (metafile) flags.push(`--metafile`)\n  if (outfile) flags.push(`--outfile=${outfile}`)\n  if (outdir) flags.push(`--outdir=${outdir}`)\n  if (outbase) flags.push(`--outbase=${outbase}`)\n  if (tsconfig) flags.push(`--tsconfig=${tsconfig}`)\n  if (packages) flags.push(`--packages=${packages}`)\n  if (resolveExtensions) flags.push(`--resolve-extensions=${validateAndJoinStringArray(resolveExtensions, 'resolve extension')}`)\n  if (publicPath) flags.push(`--public-path=${publicPath}`)\n  if (entryNames) flags.push(`--entry-names=${entryNames}`)\n  if (chunkNames) flags.push(`--chunk-names=${chunkNames}`)\n  if (assetNames) flags.push(`--asset-names=${assetNames}`)\n  if (mainFields) flags.push(`--main-fields=${validateAndJoinStringArray(mainFields, 'main field')}`)\n  if (conditions) flags.push(`--conditions=${validateAndJoinStringArray(conditions, 'condition')}`)\n  if (external) for (let name of external) flags.push(`--external:${validateStringValue(name, 'external')}`)\n  if (alias) {\n    for (let old in alias) {\n      if (old.indexOf('=') >= 0) throw new Error(`Invalid package name in alias: ${old}`)\n      flags.push(`--alias:${old}=${validateStringValue(alias[old], 'alias', old)}`)\n    }\n  }\n  if (banner) {\n    for (let type in banner) {\n      if (type.indexOf('=') >= 0) throw new Error(`Invalid banner file type: ${type}`)\n      flags.push(`--banner:${type}=${validateStringValue(banner[type], 'banner', type)}`)\n    }\n  }\n  if (footer) {\n    for (let type in footer) {\n      if (type.indexOf('=') >= 0) throw new Error(`Invalid footer file type: ${type}`)\n      flags.push(`--footer:${type}=${validateStringValue(footer[type], 'footer', type)}`)\n    }\n  }\n  if (inject) for (let path of inject) flags.push(`--inject:${validateStringValue(path, 'inject')}`)\n  if (loader) {\n    for (let ext in loader) {","sourceCodeStart":296,"sourceCodeEnd":332,"githubUrl":"https://github.com/evanw/esbuild/blob/6ff1d8b0d8c134e867a397eef39702a223ebef9e/lib/shared/common.ts#L296-L332","documentation":"Error \"Invalid package name in alias: ${old}\" thrown in evanw/esbuild.","triggerScenarios":"Thrown at lib/shared/common.ts:314 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Use a valid package name as the alias key (no subpaths or invalid characters in the package name position)","Fix the alias map so keys are plain package names"],"exampleFix":"esbuild.buildSync({ alias: { 'react': 'preact/compat' } });","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"analyzedSha":"6ff1d8b0d8c134e867a397eef39702a223ebef9e","analyzedAt":"2026-08-03T19:42:38.433Z","schemaVersion":2}